Percentages in mathematics. Interest tasks.

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Percentages in mathematics.

What percentages in mathematics? How to decide interest tasks? These questions pop up, alas, suddenly ... When a graduate reads the USE task. And they confuse him. But in vain. These are very simple concepts.

The only thing you need to remember ironically - what is one percent . This concept is master key to solving problems with percentages, and to working with percentages in general.

One percent is one hundredth of a number . And that's it. There is no more wisdom.

Reasonable question - a hundredth part what date ? And here is the number that is being discussed in the assignment. If it talks about price, one percent is one hundredth of the price. When it comes to speed, one percent is one hundredth of the speed. Etc. It is clear that the number itself in question is always 100%. And if there is no number itself, then the percentages have no meaning ...

Another thing is that in complex problems the number itself will be hidden so that you won’t find it. But we are not aiming at the complex yet. Dealing with percentages in mathematics.

I do not in vain emphasize the words one percent, one hundredth. Remembering what is one percent, you can easily find two percent, and thirty-four, and seventeen, and one hundred and twenty-six! As much as you need, so much you will find.

And this, by the way, is the main skill for solving problems with percentages.

Shall we try?

Let's find 3% of 400. First we find one percent. This will be one hundredth, i.e. 400/100 = 4. One percent is 4. How many percent do we need? Three. So let's multiply 4 by 3. We get 12. Everything. Three percent of 400 is 12.

5% of 20 is 20 divided by 100 (one hundredth is 1%), and multiplied by five (5%):

5% of 20 will be 1. That's it.

Easier nowhere. Let's quickly, before we forget, let's practice!

Find how much will be:
5% from 200 rubles.
8% of 350 kilometers.
120% of 10 liters.
15% off 60 degrees.
4% of excellent students from 25 students.
10% losers out of 20 people.

Answers (in complete disarray): 9, 10, 2, 1, 28, 12.

These numbers are the number of rubles, degrees, students, etc. I did not write how much of what, to make it more interesting to decide ...

What if we need to write X% from some number, for example, from 50? Yes, everything is the same. One percent of 50 is how much? That's right, 50/100 = 0.5. And we have these percentages - X. So let's multiply 0.5 by X! We get that X% from 50 it is 0.5x.

I hope that is percentages in mathematics you figured it out. And you can easily find any percentage of any number. It's simple. You are now capable of about 60% of all tasks for interest! Already more than half. So, let's get the rest, shall we? Okay, whatever you say!

In problems with percentages, the reverse situation is often encountered. We are given quantities (whatever), but you need to find interest . Let's master this simple process.

3 people out of 120 - how many percent? Do not know? Well then, let it be X percent.

Compute X% from 120 people. In people. This is what we can do. 120 divided by 100 (calculate 1%) and multiply by X(calculate X%). We get 1.2 X.

Let's consider the result.

X percent from 120 people, this is 1.2 X Human . And we have three such people. It remains to compare:

We recall that for x we ​​took the number of percent. So 3 people out of 120 people is 2.5%.

That's all.

It is possible in another way. Get by with simple ingenuity, without any equations. Thinking how many times 3 people less than 120? We divide 120 by 3 and get 40. So 3 is less than 120 by 40 times.

The desired number of people in percent will be the same amount less than 100%. After all, 120 people - this is 100%. Divide 100 by 40, 100/40 = 2.5

That's all. Got 2.5%.

There is another method of proportions, but this is, in essence, the same thing in an abbreviated version. All of these methods are correct. As you feel more comfortable, more familiar, more understandable - so consider.

We are training again.

Calculate what percentage is:
3 people out of 12.
10 rubles from 800.
4 textbooks of 160 books.
24 correct answers to 32 questions.
2 correct answers to 32 questions.
9 hits out of 10 shots.

Answers (in disarray): 75%, 25%, 90%, 1.25%, 2.5%, 6.25%.

In the process of calculations, you may well encounter fractions. Including uncomfortable ones, such as 1.333333... And who told you to use a calculator? yourself? No need. Consider without calculator , as written in the "Fractions" topic. There are all sorts of percentages...

So we have mastered the transition from values ​​​​to percentages and vice versa. You can take on tasks.

Interest tasks.

In the exam, problems with percentages are very popular. From the simplest to the most complex. In this section, we work with simple tasks. In simple problems, as a rule, you need to move from percentages to those values ​​that are discussed in the problem. To rubles, kilograms, seconds, meters, and so on. Or vice versa. This we already know. After that, the problem becomes clear and easily solved. Don't believe? See for yourself.
Let us have such a problem.

“The bus ride costs 14 rubles. During the school holidays, a 25% discount was introduced for students. How much is the bus fare during the school holidays?

How to decide? If we find out how much 25% in rubles- then there is nothing to decide. Subtract the discount from the original price - and that's it!

But we already know how to do it! How much will one percent from 14 rubles? One hundredth part. That is, 14/100 = 0.14 rubles. And we have 25 such percentages. So we multiply 0.14 rubles by 25. We get 3.5 rubles. That's all. We have set the discount amount in rubles, it remains to find out the new fare:

14 – 3,5 = 10,5.

Ten and a half rubles. This is the answer.

As soon as they switched from interest to rubles, everything became simple and clear. This is a general approach to solving percentage problems.

Of course, not all tasks are equally elementary. There are more difficult ones. Think! We will solve them now. The problem is that it's the other way around. We are given some values, but we need to find percentages. For example, such a task:

“Before, Vasya solved two problems correctly for percentages out of twenty. After studying the topic on one useful site, Vasya began to solve 16 problems out of 20 correctly. By what percentage did Vasya become smarter? We consider 20 solved tasks as one hundred percent intelligence.

Since the question is about percentages (and not rubles, kilograms, seconds, etc.), then we turn to percentages. Find out how many percent Vasya solved before wondering how many percent after - and it's in the hat!

We consider. Two problems out of 20 - how many percent? 2 is less than 20 by 10 times, right? So the number of tasks in percentages will be 10 times less than 100%. So 100/10 = 10.

ten%. Yes, Vasya decided a little ... There is nothing to do at the Unified State Examination. But now he has grown wiser, and solves 16 tasks out of 20. We consider how many percent it will be? How many times is 16 less than 20? You can’t say offhand ... You’ll have to share.

5/4 times. Well, now we divide 100 by 5/4:

Here. 80% is already solid. And most importantly - there is no limit!

But that's not the answer! We read the problem again, so as not to make a mistake out of the blue. Yes, we are asked how much percent wiser Vasya? Well, it's simple. 80% - 10% = 70%. At 70%.

70% is the correct answer.

As you can see, in simple tasks it is enough to convert the given values ​​into percentages, or the given percentages into values, as everything becomes clear. It is clear that there may well be additional bells and whistles in the problem. Which, often, have nothing to do with interest at all. Here, most importantly, carefully read the condition and step by step, slowly, unfold the problem. We will talk about this in the next topic.

But there is one serious ambush in problems for percentages! Many fall into it, yes ... This ambush looks quite innocent. For example, here is a problem.

“A beautiful notebook cost 40 rubles in the summer. Before the start of the school year, the seller raised the price by 25%. However, notebooks began to buy so badly that he reduced the price by 10%. Still don't take it! He had to reduce the price by another 15%. Here comes the trade! What was the final price of the notebook?”

Well, how? Elementary?

If you promptly and joyfully gave the answer “40 rubles!”, Then you were ambushed ...

The trick is that percentages are always calculated from something .

Here we consider. How much rubles did the seller raise the price? 25% from 40 rubles - it's 10 rubles. That is, the increased price of a notebook began to cost 50 rubles. It's understandable, right?

And now we need to drop the price by 10% from 50 rubles. From 50, not 40! 10% of 50 rubles is 5 rubles. Consequently, after the first reduction in price, the notebook began to cost 45 rubles.

We consider the second reduction in price. 15% from 45 rubles ( from 45, not 40, or 50! ) is 6.75 rubles. So, the final price of the notebook:

45 - 6.75 = 38.25 rubles.

As you can see, the ambush lies in the fact that interest is calculated each time from the new price. From the last. This happens almost always. If the task for a sequential increase-decrease in a value is not explicitly stated, from what to calculate percentages, it is necessary to calculate them from the last value. And that's true. How does the seller know how many times this notebook went up and down in price before him and how much it cost at the very beginning ...

By the way, now you may think why the last phrase is written in the puzzle about clever Vasya? This one: " We consider 20 solved problems to be one hundred percent smart”? It seems that everything is clear anyway ... Uh-uh ... How to say. If this phrase does not exist, Vasya may well count his initial successes as 100%. That is two solved problems. And 16 tasks - eight times more. Those. 800%! Vasya will be able to justifiably talk about his own wisdom as much as 700%!

And you can also take 16 tasks for 100%. And get a new answer. Also correct...

Hence the conclusion: the most important thing in tasks for percentages is to clearly define what this or that percentage should be calculated from.

This, by the way, is necessary in life. where interest is used. In stores, banks, at all sorts of promotions. And then you wait for a 70% discount, but you get 7%. And not discounts, but rises in price ... And everything is honest, he himself miscalculated.

Well, you got an idea about percentages in mathematics. Let's note the most important.

Practical Tips:

1. In problems with percentages, we move from percentages to specific values. Or, if necessary, from specific values ​​to percentages. Read the task carefully!

2. We study very carefully, from what interest must be calculated. If this is not stated directly, then it is necessarily implied. When changing a value successively, percentages are assumed from the last value. We carefully read the task!

3. Having finished solving the problem, we read it again. It is possible that you have found an intermediate answer, and not a final one. We carefully read the task!

Solve several percentage problems. For reinforcement, so to speak. In these puzzles, I tried to collect all the main difficulties that await the decisive ones. Those rakes that are most often stepped on. Here they are:

1. Elementary logic in the analysis of simple problems.

2. The correct choice of the value from which you want to calculate the percentage. How many people stumbled on this! But there is a very simple rule...

3. Interest on interest. A trifle, but confuses great ...

4. And one more pitchfork. Relationship of percentages with fractions and parts. Translation of them into each other.

“50 people took part in the Mathematics Olympiad. 68% of students solved few problems. 75% of the rest solved the average, and the rest - a lot of problems. How many people solved many problems?

Clue. If you get fractional students, this is wrong. Read the problem carefully, there is one important word there ... Another problem:

“Vasya (yes, the same one!) Loves donuts with jam very much. Which are baked at the bakery, one stop from the house. Donuts cost 15 rubles apiece. Having 43 rubles available, Vasya went to the bakery by bus for 13 rubles. And in the bakery there was an action "Discount for everything - 30%!!!". Question: how many additional donuts Vasya could not buy because of his laziness (he could have walked on foot, right?)”

Short puzzles.

What percentage is 4 less than 5?

How many percent is 5 greater than 4?

Long task...

Kolya got a simple job related to the calculation of interest. During the interview, the boss with a sly smile offered Kolya two options for remuneration. According to the first option, Kolya was immediately assigned a rate of 15,000 rubles per month. According to the second Kolya, if he agrees, the first 2 months will be paid a salary reduced by 50%. Kind of like a newbie. But then they will increase his reduced salary by as much as 80%!

Kolya visited one useful site on the Internet ... Therefore, after thinking for six seconds, he chose the first option with a slight smile. The boss smiled back and set Kolya a fixed salary of 17,000 rubles.

Question: How much money per year (in thousands of rubles) did Kolya win at this interview? When compared with the most unfortunate option? And one more thing: why are they smiling all the time!?)

Another short puzzle.

Find 20% of 50%.

And again long.)

Fast train No. 205 "Krasnoyarsk - Anapa" made a stop at the station "Syzran-Gorod". Vasily and Kirill went to the railway station shop for ice cream for Lena and a hamburger for themselves. When they bought everything they needed, the store cleaner said that their train had already left ... Vasily and Kirill quickly ran and managed to jump into the car. Question: under these conditions, would the world champion in running have time to jump into the car?
We believe that under normal conditions the world champion runs 30% faster than Vasily and Kirill. However, the desire to catch up with the car (it was the last one), treat Lena with ice cream and eat a hamburger increased their speed by 20%. And ice cream with a hamburger in the hands of a champion and flip-flops on his feet would reduce his speed by 10%...

But the problem without interest ... I wonder why she is here?)

Determine how much 3/4 of an apple weighs if the whole apple weighs 200 grams?

And the last one.

In the fast train No. 205 "Krasnoyarsk - Anapa", fellow travelers were solving a scanword. Lena guessed 2/5 of all the words, and Vasily guessed one third of the rest. Then Cyril connected and solved 30% of the entire scanword! Seryozha guessed the last 5 words. How many words were in the scanword? Is it true that Lena guessed the most words?

Answers in the traditional disorder and without unit names. Where are the donuts, where are the students, where are the rubles with interest - it's you yourself ...

ten; fifty; Yes; 4; 20; No; 54; 2; 25; 150.

So how? If everything fits together, congratulations! Interest is not your problem. You can safely go to work in a bank.)

Something is wrong? Does not work? Don't know how to quickly calculate percentages of a number? Do not know very simple and clear rules? From what to count percentages, for example? Or how to convert fractions to percentages?

If you like this site...

By the way, I have a couple more interesting sites for you.)

You can practice solving examples and find out your level. Testing with instant verification. Learning - with interest!)

you can get acquainted with functions and derivatives.

In this lesson, you will see how to quickly calculate percentages using Excel, get acquainted with the basic formula for calculating percentages, and learn a few tricks that will make your work with percentages easier. For example, the formula for calculating the percentage increase, calculating the percentage of the total amount, and something else.

The ability to work with percentages can be useful in various areas of life. This will help you estimate the amount of tips in a restaurant, calculate commissions, calculate the profitability of an enterprise and the degree of your personal interest in this enterprise. Tell me honestly, will you be happy if you are given a promotional code for a 25% discount for buying a new plasma? Sounds tempting, right?! And how much do you actually have to pay, can you calculate?

In this tutorial, we'll show you a few techniques that will help you easily calculate percentages with Excel, as well as introduce you to the basic formulas that are used to work with percentages. You will learn some tricks and you will be able to hone your skills by deciphering solutions to practical percentage problems.

Basic knowledge about percentages

Term Percent(per cent) came from Latin (per centum) and was originally translated as FROM A HUNDRED. In school, you learned that a percentage is a part of 100 parts of a whole. The percentage is calculated by dividing, where the numerator of the fraction is the desired part, and the denominator is the whole, and then the result is multiplied by 100.

The basic formula for calculating interest looks like this:

(Part/Whole)*100=Percentage

Example: You had 20 apples, of which you distributed 5 to your friends. What percentage of your apples did you give away? Having made simple calculations, we get the answer:

(5/20)*100 = 25%

This is how you were taught to calculate percentages in school, and you use this formula in your daily life. Calculating percentages in Microsoft Excel is an even easier task, since many mathematical operations are performed automatically.

Unfortunately, there is no universal formula for calculating interest for all occasions. If you ask the question: what percentage formula to use to get the desired result, then the most correct answer will be: it all depends on what result you want to get.

I want to show you some interesting percentage formulas. These are, for example, the formula for calculating the percentage increase, the formula for calculating the percentage of the total amount, and some other formulas that you should pay attention to.

The basic formula for calculating interest in Excel

The basic formula for calculating interest in Excel looks like this:

Part/Whole = Percentage

If you compare this formula from Excel with the familiar formula for percentages from the math course, you will notice that it does not multiply by 100. When calculating percentage in Excel, you do not need to multiply the result of division by 100, as Excel will do this automatically if for a cell given Percent Format.

Now let's see how the calculation of percentages in Excel can help in real work with data. Let's say that in column B you have a certain number of ordered products (Ordered), and in column C you have entered data on the number of delivered products (Delivered). To calculate what percentage of orders have already been delivered, we will do the following:

• Write down the formula =C2/B2 in cell D2 and copy it down as many lines as needed using the autofill handle.
• Click command Percent Style(Percentage Format) to display division results in percent format. It's on the tab Home(Home) in a command group number(Number).
• If necessary, adjust the number of displayed characters to the right of the decimal point.
• Ready!

If you use any other formula to calculate percentages in Excel, the general sequence of steps will remain the same.

In our example, column D contains values ​​that indicate, as a percentage, what percentage of the total number of orders are orders already delivered. All values ​​are rounded to whole numbers.

Calculate percentage of total amount in Excel

In fact, the example given is a special case of calculating a percentage of the total amount. To better understand this topic, let's look at a few more tasks. You will see how you can quickly calculate the percentage of the total in Excel using various data sets as an example.

Example 1. The total amount is calculated at the bottom of the table in a specific cell

Very often, at the end of a large table of data, there is a cell labeled Total, in which the total is calculated. At the same time, we are faced with the task of calculating the share of each part relative to the total amount. In this case, the formula for calculating the percentage will look the same as in the previous example, with one difference - the reference to the cell in the denominator of the fraction will be absolute (with $ signs before the row name and column name).

For example, if you have some values ​​\u200b\u200bwritten in column B, and their total is in cell B10, then the percentage calculation formula will be as follows:

Clue: There are two ways to make the cell reference in the denominator absolute: either enter the sign $ manually, or select the desired cell reference in the formula bar and press the key F4.

The figure below shows the result of calculating the percentage of the total. Percentage format with two decimal places is selected for data display.

Example 2: Parts of the grand total are on multiple lines

Imagine a data table like the previous example, but here the product data is spread across multiple rows of the table. It is required to calculate what part of the total amount is the orders of a particular product.

In this case, we use the function SUMIF(SUMIS). This function allows you to summarize only those values ​​that meet some specific criterion, in our case, this is a given product. The result is used to calculate the percentage of the total.

SUMIF(range,criteria,sum_range)/total
=SUMIF(range, criteria, sum_range)/total sum

In our example, column A contains the names of products (Product) - this is range. Column B contains quantity data (Ordered) - this is sum_range. In cell E1 we enter our criterion– the name of the product for which you want to calculate the percentage. The total amount for all products is calculated in cell B10. The working formula will look like this:

SUMIF(A2:A9,E1,B2:B9)/$B$10
=SUMIF(A2:A9,E1,B2:B9)/$B$10

By the way, the name of the product can be entered directly into the formula:

SUMIF(A2:A9,"cherries",B2:B9)/$B$10
=SUMIF(A2:A9,"cherries",B2:B9)/$B$10

If you need to calculate how much of the total is made up of several different products, you can sum the results for each of them, and then divide by the total. For example, this is how the formula would look if we want to calculate the result for cherry and apples:

=(SUMIF(A2:A9,"cherries",B2:B9)+SUMIF(A2:A9,"apples",B2:B9))/$B$10
=(SUMIF(A2:A9;"cherries";B2:B9)+SUMIF(A2:A9;"apples";B2:B9))/$B$10

How to calculate percentage change in Excel

One of the most popular tasks that you can do with Excel is calculating the percentage change in data.

Excel formula that calculates percentage change (increase/decrease)

(B-A)/A = Percent change

When using this formula in real data, it is very important to correctly determine which value to put in place. A, and which one is in place B.

Example: Yesterday you had 80 apples and today you have 100 apples. This means that today you have 20 more apples than yesterday, that is, your result is an increase of 25%. If yesterday there were 100 apples, and today 80, then this is a decrease of 20%.

So, our formula in Excel will work as follows:

(New value - Old value) / Old value = Percent change

Now let's see how this formula works in Excel in practice.

Example 1: Calculate percentage change between two columns

Let's assume that column B contains the prices of the last month (Last month), and column C contains the prices that are current this month (This month). In column D, we will enter the following formula to calculate the price change from the previous month to the current one as a percentage.

This formula calculates the percentage change (increase or decrease) in the price this month (column C) compared to the previous month (column B).

After you write the formula in the first cell and copy it to all the necessary lines by dragging the autofill marker, do not forget to set Percent Format for cells with a formula. As a result, you should get a table similar to the one shown in the figure below. In our example, positive data, which shows an increase, is displayed in standard black, and negative values ​​(percentage decrease) are highlighted in red. For details on how to set up such formatting, read this article.

Example 2: Calculate percentage change between rows

In the case where your data is located in one column, which reflects sales information for a week or a month, the percentage change can be calculated using the following formula:

Here C2 is the first value and C3 is the next value.

Comment: Please note that, with this arrangement of data in the table, the first line with data must be skipped and the formula must be written from the second line. In our example, this will be cell D3.

After you write down the formula and copy it into all the necessary rows of your table, you should get something similar to this:

For example, this is how the formula for calculating the percentage change for each month in comparison with the indicator would look like January(January):

When you copy your formula from one cell to all the others, the absolute reference will remain the same, while the relative reference (C3) will change to C4, C5, C6, and so on.

Calculation of the value and the total amount by a known percentage

As you can see, calculating percentages in Excel is easy! It is just as easy to calculate the value and the total amount by a known percentage.

Example 1: Calculate a value from a known percentage and total amount

Let's say you buy a new computer for $950, but add another 11% VAT to that price. The question is how much do you need to pay? In other words, 11% of the indicated value is how much in currency?

The following formula will help us:

Total * Percentage = Amount
Total Amount * Interest = Value

Let's pretend that total amount(Total) is written in cell A2, and Interest(Percent) - in cell B2. In this case, our formula will look quite simple =A2*B2 and give the result $104.50 :

Important to remember: When you manually enter a numeric value into a table cell followed by a % sign, Excel interprets this as hundredths of the entered number. That is, if you enter 11% from the keyboard, then in fact the cell will store the value 0.11 - this is the value Excel will use when making calculations.

In other words, the formula =A2*11% is equivalent to the formula =A2*0.11. Those. in formulas, you can use either decimal values ​​or values ​​with a percent sign - as you prefer.

Example 2. Calculate the total amount from a known percentage and value

Let's say your friend offered to buy his old computer for $400 and said it was 30% off its full price. Do you want to know how much this computer originally cost?

Since 30% is a price reduction, the first step is to subtract this value from 100% to calculate how much of the original price you need to pay:

Now we need a formula that will calculate the initial price, that is, find the number, 70% of which is equal to $400. The formula will look like this:

Amount/Percentage = Total
Value/Percentage = Total Amount

To solve our problem, we get the following form:

A2/B2 or =A2/0.7 or =A2/70%

How to increase/decrease value by percentage

With the onset of the holiday season, you notice some changes in your usual weekly spending items. You may want to make some additional adjustments to how your spending limits are calculated.

To increase a value by a percentage, use the following formula:

Value*(1+%)

For example, the formula =A1*(1+20%) takes the value contained in cell A1 and increases it by 20%.

To decrease a value by a percentage, use the following formula:

Value*(1-%)

For example, the formula =A1*(1-20%) takes the value contained in cell A1 and reduces it by 20%.

In our example, if A2 is your current expenses, and B2 is the percentage by which you want to increase or decrease their value, then you need to write the following formula in cell C2:

Increase by percentage: =A2*(1+B2)
Decrease by percentage: =A2*(1-B2)

How to increase/decrease by percentage all values ​​in a column

Suppose you have a whole column filled with data that needs to be increased or decreased by some percentage. However, you do not want to create another column with a formula and new data, but change the values ​​in the same column.

We need only 5 steps to solve this problem:

In both formulas, we took 20% as an example, and you can use the percentage value that you need.

As a result, the values ​​in column B will increase by 20%.

In this way, you can multiply, divide, add, or subtract some percentage from a whole column of data. Just enter the desired percentage in an empty cell and follow the steps described above.

These methods will help you in calculating percentages in Excel. And even if percentages have never been your favorite section of mathematics, knowing these formulas and tricks will make Excel do all the work for you.

That's all for today, thank you for your attention!

In various activities, the ability to calculate percentages is necessary. Understand how they "get". Trading allowances, VAT, discounts, returns on deposits, securities, and even tips are all calculated as some part of the whole.

Let's understand how to work with percentages in Excel. A program that performs calculations automatically and allows variations of the same formula.

Working with percentages in Excel

Calculating a percentage of a number, adding, subtracting interest on a modern calculator is not difficult. The main condition is that the corresponding icon (%) must be on the keyboard. And then - a matter of technique and attentiveness.

For example, 25 + 5%. To find the value of an expression, you need to type a given sequence of numbers and signs on the calculator. The result is 26.25. You don't need to be smart with this technique.

To create formulas in Excel, let's remember the school basics:

A percentage is a hundredth of a whole.

To find the percentage of a whole number, you need to divide the desired share by the whole number and multiply the total by 100.

Example. Brought 30 units of goods. On the first day, 5 units were sold. What percentage of the product was sold?

5 is a part. 30 is an integer. We substitute the data in the formula:

(5/30) * 100 = 16,7%

To add a percentage to a number in Excel (25 + 5%), you must first find 5% of 25. At school, they made up the proportion:

X \u003d (25 * 5) / 100 \u003d 1.25

After that, you can perform addition.

When basic computing skills are restored, it will not be difficult to figure out the formulas.



How to calculate percentage of a number in Excel

There are several ways.

We adapt the mathematical formula to the program: (part / whole) * 100.

Look carefully at the formula bar and the result. The result is correct. But we did not multiply by 100. Why?

Cell format changes in Excel. For C1, we assigned the "Percentage" format. It involves multiplying the value by 100 and displaying it with a % sign. If necessary, you can set a certain number of digits after the decimal point.

Now let's calculate how much it will be 5% of 25. To do this, enter the calculation formula into the cell: \u003d (25 * 5) / 100. Result:

Or: =(25/100)*5. The result will be the same.

Let's solve the example in a different way, using the % sign on the keyboard:

Let's apply the acquired knowledge in practice.

The cost of the goods and the VAT rate (18%) are known. You need to calculate the amount of VAT.

Multiply the cost of the item by 18%. Let's "multiply" the formula to the entire column. To do this, click on the bottom right corner of the cell and drag it down.

The amount of VAT, the rate is known. Let's find the cost of the goods.

Calculation formula: =(B1*100)/18. Result:

The quantity of goods sold, individually and in total, is known. It is necessary to find the share of sales for each unit relative to the total.

The calculation formula remains the same: part / whole * 100. Only in this example, we will make the reference to the cell in the denominator of the fraction absolute. Use the $ sign before the row name and column name: $B$7.

How to add a percentage to a number

The problem is solved in two steps:

And here we have performed the actual addition. We omit the intermediate action. Initial data:

The VAT rate is 18%. We need to find the amount of VAT and add it to the price of the goods. Formula: price + (price * 18%).

Don't forget the brackets! With their help, we establish the order of calculation.

To subtract a percentage from a number in Excel, follow the same procedure. Only instead of addition, we perform subtraction.

How to calculate percentage difference in Excel?

How much the value has changed between two values ​​as a percentage.

Let's abstract from Excel first. A month ago, tables were brought to the store at a price of 100 rubles per unit. Today the purchase price is 150 rubles.

Percent difference = (new data - old data) / old data * 100%.

In our example, the purchase price of a unit of goods increased by 50%.

Let's calculate the percentage difference between the data in the two columns:

Do not forget to set the "Percentage" cell format.

Calculate the percentage change between rows:

The formula is: (next value - previous value) / previous value.

With this arrangement of data, we skip the first line!

If you need to compare data for all months with January, for example, use an absolute cell reference with the desired value ($ sign).

How to make a percentage chart

First option: make a column in the data table. Then use this data to build a chart. Select the cells with percentages and copy - click "Insert" - select the chart type - OK.

The second option is to format the data labels as a share. In May - 22 working shifts. You need to calculate in percentage: how much each worker worked. We compile a table where the first column is the number of working days, the second is the number of days off.

Let's make a pie chart. Select the data in two columns - copy - "Insert" - chart - type - OK. Then we insert the data. Click on them with the right mouse button - "Format Data Signatures".

Select "Shares". On the "Number" tab - percentage format. It turns out like this:

We will stop there. And you can edit to your taste: change the color, the appearance of the diagram, make underlines, etc.

Sometimes calculating percentages can be difficult, because it is not always easy to remember what we were taught in school. Let Excel do the work for you - simple formulas can help you find things like the percentage of a total or the percentage difference between two numbers.

Important: The calculated results of formulas and some Excel worksheet functions may be slightly different between Windows x86 or x86-64 computers and Windows RT ARM computers.

Let's say your company sold $125,000 worth of goods this quarter and you need to calculate what percentage of $20,000 is of the total.

In 2011, the company sold goods in the amount of 485,000 rubles, and in 2012 - in the amount of 598,634 rubles. What is the difference between these percentages?

see also

Calculating the Percentage of the Total Value

Let's say that you answered 42 questions out of 50 correctly on the test. What is the percentage of correct answers?

Calculating the difference between two numbers as a percentage

Suppose your salary was 23,420 rubles in November and 25,000 rubles in December. By what percent did your salary change in December compared to November? Then, if in January you earned 24,250 rubles, then by how many percent does this differ from December? You can calculate the difference by subtracting the new salary from the previous salary and then dividing the result by the sum of the previous salary.

Magnification Percentage Calculation

Reduction Percentage Calculation

Finding the Total Value with a Known Count and Percentage

Assume that the selling price of a shirt is $15, which is 25% below the original price. What is the initial price? In this example, you need to find a number, 75% of which is 15.

Finding the sum when you know the total and the percentage

If you purchase a computer for $800, you must pay an additional 8.9% sales tax. How much will this tax be? In this example, you need to find 8.9% of 800.

Increase or decrease a number by a given percentage

We spend an average of $113 per week on food, and we need to reduce this cost by 25%. How much can you spend on a weekly basis? Alternatively, there is an option to increase the $113 weekly limit by 25%. How much will the food cost per week be in this case?

In the process of solving various kinds of tasks, both educational and practical, users often turn to Excel.

Spreadsheets allow you to analyze data, build charts and graphs, and perform a variety of calculations. One common operation is the calculation of percentages. The ability to competently make the necessary calculations is a useful skill that finds successful application in almost all areas of life. What techniques will help you calculate percentages using Excel spreadsheets?

How to calculate percentages in Excel - the basic calculation formula

Before proceeding with the calculation of percentages, it is necessary to define the terminology. The term "percentage" means the number of shares out of all 100 shares of the whole. The mathematical definition of a percentage is a fraction, the numerator of which determines the desired number of parts, and the denominator is the total. The result is multiplied by 100 (because the integer is 100%). Working with a spreadsheet, the formula for determining the percentage is as follows:

Part/Whole = Percentage

It differs from the usual interpretation in mathematics only by the absence of further multiplication by 100. The properties of the table fields will help you get the necessary value format - just activate the Percent cell format.

Example 1

Here is a series of data entered, for example, in column D (D2, D3, D4, D5, ...). It is necessary to calculate, 5% of each value.

• Activate the cell next to the first value (or any other) - it will contain the result of the calculations.
• In cell E2, write the expression "=D2/100*5" or "=D2*5%".
• Press Enter.
• "Drag" cell E2 to the required number of lines. Thanks to the autocomplete token, the above formula will also calculate the rest of the values.

Example 2

You have 2 columns of values ​​in front of you - for example, sold cakes (D2, D3, D4, D5, ...) and the total number of baked goods (E2, E3, E4, E5, ...) of each type. It is necessary to determine what part of the product is sold.

• In the cell where the result will be calculated (for example, F), write the expression "=D2/E2".
• Press Enter and "stretch" the cell for the required number of lines. Using the autofill marker will allow you to apply this formula to all subsequent cells and make the correct calculations.
• To convert the result to percentage format, select the required cells and use the Percent Style command. To activate the latter, you can right-click and select the "Format cells" - "Percentage" item in the list that appears. In doing so, you specify the desired number of decimal places. Or go to the "Home" - "Number" section and select the "Percentage" view.

How to calculate percentages in Excel - percentage of the amount

To calculate the proportion of each part relative to the total, use the expression "=A2/$A$10", where A2 is the value of interest, the total is indicated in cell A10. What if the position you are interested in appears in the table several times? In this case, use the SUMIF (SUMIF) function with the following parameters:

SUMIF(range,criteria,sum_range)/total

SUMIF(range, criterion, sum_range)/total sum

• Move to the cell where the result will be obtained.
• Write the expression "=SUMIF(C2:C10;F1;D2:D10)/$D$14" (or =SUMIF (C2:C10;F1;D2:D10)/$D$14), where

C2:C10, D2:D10 - ranges of values ​​within which calculations occur,

F1 - a cell in which the studied characteristic is indicated,

D14 is the cell in which the amount is calculated.

How to Calculate Percentages in Excel - Percent Change

The need for such calculations often arises in the course of assessing the increase or decrease in performance. So, sales volumes by product categories for 2015. entered in column D, similar data for 2016. - in column E. It is necessary to determine by what percentage the volume of sales increased or decreased.

• In cell F2, enter the formula "=(E2-D2)/D2".
• Convert cell data to Percentage format.
• To calculate the increase or decrease for the remaining categories (cells), stretch F2 for the required number of lines.
• Evaluate the result. If the value is positive, you have an increase; if negative, you have a decrease.