Percents are used to describe a part of something. Percents are used to figure out sales or the amount of interest someone will pay on a loan. When converting a percent to its fraction form, it will always have a denominator of 100.
Changing Decimals to Percents or Percents to Decimals
The important key is where to move the decimal point. If changing from decimal to a percent , you would need to move the decimal point two places to the right and add the percent sign.
0.35 = 35%
0.8 = 80%
To change from percent to decimal, need to move the decimal point two places to the left and drop the percent sign.
30% = .3
0.9% = .009
Converting Fraction to Percent Form
Divide the bottom number of the fraction into the top number and move the point two places to the right.
Multiply the fraction by 100%
Percent to Fraction
Write the percent as a fraction with 100 as the denominator. Then reduce the fraction to lowest terms.
Percent of a Number
Finding What Percent One Number Is of Another
There are key words to remember that will help you solve the problem it is asking you. The word of in the sentence means to multiply. The word is means it is equal to.
Example: 9 is what percent of 45 The variable a is being multiplied by 45. Need to divide by 45. 9 = a (x) 45 9 = 45a
The variable a is being multiplied by 45. Need to divide by 45.
Therefore, 20% of 45 is 9.
Finding a Number When a Percent of It is Given
Example: 20% of what number is 16?
Change the percent to fraction form.
Need to multiply both sides of the equation by 5.