How to find the percentage?
Knowing how to find interest, you needevery person. Tasks for finding the interest life sets us constantly and, sometimes, several times a day. This is the percentage of discount in the store, and interest on bank deposits, and much more.
Before you understand how to find interest, you need to define this mathematical concept. So, one hundredth part of any number is called a percentage.
How to find the percentage of the number
Suppose we need to solve the problem: "The store declares a 5% discount. How much cheaper is the skirt now, the original price of which was 300 rubles? " To solve this problem, we need to calculate how many rubles will be 5% of 300 rubles, i.e. find a percentage of the number.
As we have already said, the percentage is the hundredth part of any number. Then we calculate how much is 1% of 300 rubles. To do this, divide 300 by one hundred. It turns out that 1% of 300 is 3.
Now that we know what is equal to 1%, we can easily calculate how many rubles will be 5% of 300 rubles. You just need to do the following: 3 * 5 = 15 (rubles).
Thus, the skirt was cheaper by 15 rubles.
It is even easier to find a percentage of the number using a proportion.
300 rubles - 100%
X rubles - 5%
Hence X = (300 * 5) / 100 = 15 rubles.
How to find a percentage of the amount
Find the percentage of the amount is very easy. First, add all the summands. Then the received sum is divided into one hundred, and the result is multiplied by the number of percent, which is specified by the conditions of the task.
For example, you need to find 7% of the sum of numbers 35 and 42.
- 35 + 42 = 77
- 77: 100 = 0.77
- 0.77 * 7 = 5.39
How to find interest using a calculator
To understand and remember how to find interest using a calculator is easiest for a specific example. To do this, let's find 9% of 749.
On the calculator, multiply the number fromwhich we find percentages per number of percentages and click the "%" icon. We draw your attention that when calculating interest on the calculator, you do not need to press the "=" key.
How it looks in our example: 749 * 9%. If everything is typed correctly, the number "67.41" appears on the screen, which is the answer of this task.