What is 5/9 of 20?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/9 of 20? We'll show you a straightforward method to achieve that.

How to calculate 5/9 of 20?

  1. Multiply the whole number by the numerator of the fraction: 20 × 5 = 100
  2. Divide this result by denominator of the fraction: 100/9 = 11.111111111111

Since 100/9 is an improper fraction, the result could also be expressed as a mixed number: 11 1/9

How does it work?

The principle behind finding a fraction of a number, such as 5/9 of 20, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 9 = x 20 (where x represents 5/9 of 20)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 20 = 9 x
  2. Which gives: 100 = 9 x
  3. Divide both sides by 9 to isolate x: 100 9 = 9 x 9
  4. Which gives the result: 100 9 = x

Thus, 5/9 of 20 is equal to 100/9 (or 11.111111111111 in its decimal form).