15% = 15/100 = 0.15
Fifteen percent is the same as the fraction 15/100 and the decimal 0.15. They all simply mean "fifteen out of a hundred." A percent can always be written as a decimal, and a decimal can be written as a percent, like this:
0.85 = 85%
We can find any percent of a given number by changing the percent to a decimal and multiplying. One hundred percent of a number is just the number itself. Two hundred percent of a number is twice that number.
100% of 50 -> 50
200% of 50 -> 2 x 50 = 100
Let's find 30 percent of 400:
First change 30% to a decimal by moving the decimal point 2 places to the left.
30% = 0.30
Then multiply.
0.30 x 400 = 120
30% of 400 is 120.
