Finding a percent of a number

The rule of finding a percentage is the same as finding a fraction of a number.

To find the percentage of something, divide it by 100 parts and multiply the resulting number by the desired percentage.

For example, find 2% of 10 cm.

What does the entry 2% mean ? The entry 2% replaces the entry . If we translate this assignment into more comprehensible language, it would look like this:

Find of 10 cm

And we already know how to solve such problems. To find a fraction of a number, divide the number by the denominator of the fraction, and multiply the result by the numerator of the fraction.

So, we divide the number 10 by the denominator of the fraction

We got 0.1. Now multiply 0.1 by the numerator of the fraction

0.1 × 2 = 0.2

The answer is 0.2. So 2% of 10 cm is 0.2 cm. And if you convert 0.2 centimeters to millimeters, you get 2 millimeters:

0.2 cm = 2 mm

So 2% of 10 cm is 2 mm.

Example 2. To find 50% of $300.

To find 50% of $300, you need to divide $300 by 100, and multiply the result by 50.

So, divide $300 by 100.

300 : 100 = 3

Now multiply the result by 50

3 × 50 = $150

So 50% of $300 is $150.

If at first it is difficult to get used to the entry with the % sign, you can replace this entry with the usual fractional notation.

For example, the same 50% can be replaced by the entry . Then the problem would look like this: Find of $300, and solving such problems is so far easier for us

300 : 100 = 3

3 × 50 = $150

There is nothing complicated here. If difficulties arise, we advise you to stop and revise fractions and how they can be applied.

Example 3. A garment factory has produced 1,200 suits. Of these, 32% are new suit styles. How many new suit styles did the factory produce?

Here you should find 32% of 1200. The resulting number will be the answer to the question. Use the rule of finding the percentage. Divide 1200 by 100 and multiply the result by the desired percentage, i.e. 32

1200 : 100 = 12

12 × 32 = 384

Answer: 384 suits of the new style were produced by the factory.

The second way to find the percentage

The second way to find the percentage is much easier and more convenient. It consists in the fact that we should multiply the number (from which we are looking for the percentage) by the desired percentage, expressed as a decimal.

For example, let's solve the previous problem this way. Find 50% of $300.

The entry 50% replaces the entry , and if we convert that to a decimal we get 0.5

Now to find 50% of 300, it will be enough to multiply the number 300 by the decimal 0.5

300 × 0.5 = 150

By the way, the same principle is used to find percent on calculators. To find the percentage using a calculator, you need to enter into the calculator the number from which you are looking for the percentage, then press the multiplication key and enter the desired percentage. Then press the percent key %

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