What is 8/9 of 85?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 8/9 of 85? We'll show you a straightforward method to achieve that.

How to calculate 8/9 of 85?

  1. Multiply the whole number by the numerator of the fraction: 85 × 8 = 680
  2. Divide this result by denominator of the fraction: 680/9 = 75.555555555556

Since 680/9 is an improper fraction, the result could also be expressed as a mixed number: 75 5/9

How does it work?

The principle behind finding a fraction of a number, such as 8/9 of 85, is rooted in the method of cross-multiplication.

Consider the following proportion: 8 9 = x 85 (where x represents 8/9 of 85)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 8 × 85 = 9 x
  2. Which gives: 680 = 9 x
  3. Divide both sides by 9 to isolate x: 680 9 = 9 x 9
  4. Which gives the result: 680 9 = x

Thus, 8/9 of 85 is equal to 680/9 (or 75.555555555556 in its decimal form).