How do you use the proportion method to convert from a fraction to a percent?

You can find the percent of a number by making a proportion. A proportion is a statement that says that two fractions are equivalent. In a proportion, the cross products are equal.

Example 1:

To find the percent of a number:

 of Sidney’s paintings are portraits. 

• First, set up a proportion so that the part you want to find, the percent, is over 100.

  

• Then find the cross product by multiplying the numerator of one fraction and the denominator of the other fraction.

  

  

• Since 6 × 100 = 600, you need to find the number that 7 can be multiplied by to equal 600.

  

  

• If 7 times a number equals 600, then you can divide 600 by 7 to find the missing value.

  

  

• Now round 85.714 to the nearest whole number

  85.714 rounds to 86

• The number 86 completes the fraction that is approximately equal to .

  

Since  is 86%,  of Sydney’s paintings is approximately 86%.