# Calculating percentages in your head: what you need to know for the aptitude test

With the right formulas, calculating percentages in your head is not so difficult.

If you have received an invitation to a recruitment test in response to your application, this is actually a reason to be happy. Because you’ve already cleared the first hurdle on the way to a job. The only thing is that you might not be as enthusiastic about the typical content of the tests when you start preparing for them. Math, in particular, is a source of worry for many applicants. Especially since mental arithmetic is usually the order of the day here. And it’s not just about simple arithmetic problems, but also about things like fractions and percentages. But don’t panic: You can also quickly learn to calculate percentages in your head.

#### Test Summary

of 15 questions completed

You have already completed the test before. Hence you can not start it again.

You must first complete the following:

#### Results

Result: from points, ( )

Earned Point(s): of , ( )
Essay(s) Pending (Possible Point(s): )

#### Categories

1. Math – Percentage 0%

You have failed. Keep practicing!

• Hiring test complete course for all professions
• Actual questions from this year 2021
• All test fields present
• Step-by-step explanations of all solutions
• Online immediately feasible
• Over 3500 actual questions and answers

Passed. Practice nevertheless further!

• Employment test complete course for all professions
• Actual questions from this year 2021
• All test fields available
• Step-by-step explanations of all solutions
• Online immediately feasible
• over 3500 actual questions and answers
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
1. current
2. marked
4. correct
5. wrong

Whether you’re looking for an apprenticeship, a job or retraining, you won’t be able to avoid math in any recruitment test. Because you need math and German in every job and also in everyday life.

Although no one expects you to be a proven math genius. But certain basics should be present. And the test checks whether this is the case. There are different areas on the program. The basic arithmetic operations, the rule of three, fractions and a bit of geometry for example. And calculating with percentages is also part of it.

But you don’t just have to master percentages as such, you also have to calculate them in your head. Because calculators are rarely allowed. But don’t worry, it’s not that hard! To brush up on your knowledge from school, we explain how the percentage thing works.

## What exactly is percentage calculation??

Percentage calculation is a branch of mathematics and is closely related to interest calculation. It makes it its business to represent parts of a whole and to clarify ratios of magnitude. Percentage calculation puts quantities, units or sizes in relation to a whole.

Because percentages express proportions, they can also be written as fractions. The percent sign has the same meaning as dividing by a hundred. Therefore, a percent would have 1 in the numerator and 100 in the denominator.

An exampleSuppose you have 200 euros. These 200 euros correspond to 100 percent. One percent of this is 2 Euro, because one percent is one out of a hundred. If you would now like to put 20 percent of your money into the piggy bank, that would be 40 euros.

## The most important terms in calculating percentages

In order to be able to calculate percentages, you need to know the basic concepts of percentage calculation. Whether you calculate percentages in your head or with a calculator is irrelevant. For a task you assign the given values to the basic terms. In the next step you can then insert the values into the respective formula and calculate the task.

There are three important basic concepts in the calculation of percent:

### 1. The basic value

The basic value is the initial value to which the percentages refer. It indicates the value of the total quantity and therefore the whole. In a task, for example, this can be all the people, the entire amount of money, the entire contents of a bottle, or the entire distance from the start to the finish.

### 2. The percentage value

The percentage expresses the value of a proportion of the total quantity. It indicates how much a part is worth in relation to its basic value. For example, if there are 100 applicants in a recruitment test and 70 percent of the applicants are male, then the 100 applicants are the base value and the 70 male applicants are the percentage value.

### 3. The percentage and the percentage

The percentage indicates the relationship between the basic value and the percentage value in percent. Assume that out of 50 applicants, 30 applicants fail the recruitment test. The 50 applicants then form the basic score and the 30 applicants who do not pass form the percentage score. The percentage indicates the failure rate, in this case 60 percent.

Sometimes, however, only the percentage is used, i.e. the number of percentages without a percent sign. In this case, only the letter p is used in a formula. The percentage is the number above the fraction line when the value is written as a fraction.

## The formulas for calculating percentages

While the basic concepts of percent are very important. Only they do not bring you too much if you do not know what to do with them. Therefore, let us now look at the formulas for calculating percentages. Because you need these formulas so that you can calculate the tasks in the aptitude test.

### Calculate the basic value

While the percentage value indicates the value of a proportion and the percentage indicates the size of this proportion in relation to the total quantity, the basic value expresses the value of the total quantity.

You can get the base value by dividing the percentage W by the percentage p %. Another possibility is that you multiply the percentage value W by 100 and divide by the percentage p.

• Employment test complete course for all professions
• Actual questions from this year 2022
• All test fields available
• Step-by-step explanations of all solutions
• Online immediately feasible
• over 3500 actual questions and answers

#### An example

In this task, the total amount and thus the basic value are required. You know that Peter spent 80 Euros for the sneakers. These 80 euros are therefore the percentage value, because that is the value that the share of the total amount has. The percentage of this share is 40 percent. You can now insert the known values into the formula. This results in:

Peter received 200 euros from his grandparents as a birthday present.

### Calculating the percentage value

The percentage value quantifies the value that a certain proportion has in relation to the basic value. You can calculate the percentage value by multiplying the percentage p % by the base value G.

With this little trick you can do without the percent sign in the formula. Instead, multiply the percentage by the base value and divide the whole by 100. If you have to calculate percentages in your head for the attitude test, this might make it a little easier for you.

Since the washing machine costs 400 euros, the 400 euros are the basic value. Ms. Muller, however, receives a discount of 18 percent. Thus p % = 18 % and p = 18. Put these values into the formula, you will get the following result:

Because Mrs. Muller buys a display item and receives a discount, she must pay 72 euros less.

### Determine the percentage

Now you only need the formulas for the percentage and the percentage number. The percentage indicates the relationship between the percentage value and the basic value.

The percentage, in turn, is the percentage as a number, without the percent sign. Now one percent is a part of one hundred. Therefore, you can calculate the percentage by multiplying the percentage value by 100 and dividing by the base value. If you then add the percent sign to the result, the percent becomes the percentage.

#### A task as an example

Since the applicant weighs 80 kilos, this body weight is the base value. 4 kilograms is the part that the applicant should lose on the advice of the doctor. This proportion thus describes the percentage value. Now you put these two values into the formula again:

The applicant should reduce your body weight thus by 5 per cent.