What is 10/7 of 90?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 10/7 of 90? We'll show you a straightforward method to achieve that.

How to calculate 10/7 of 90?

  1. Multiply the whole number by the numerator of the fraction: 90 × 10 = 900
  2. Divide this result by denominator of the fraction: 900/7 = 128.57142857143

Since 900/7 is an improper fraction, the result could also be expressed as a mixed number: 128 4/7

How does it work?

The principle behind finding a fraction of a number, such as 10/7 of 90, is rooted in the method of cross-multiplication.

Consider the following proportion: 10 7 = x 90 (where x represents 10/7 of 90)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 10 × 90 = 7 x
  2. Which gives: 900 = 7 x
  3. Divide both sides by 7 to isolate x: 900 7 = 7 x 7
  4. Which gives the result: 900 7 = x

Thus, 10/7 of 90 is equal to 900/7 (or 128.57142857143 in its decimal form).