What is 7/8 of 87?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 7/8 of 87? We'll show you a straightforward method to achieve that.

How to calculate 7/8 of 87?

  1. Multiply the whole number by the numerator of the fraction: 87 × 7 = 609
  2. Divide this result by denominator of the fraction: 609/8 = 76.125

Since 609/8 is an improper fraction, the result could also be expressed as a mixed number: 76 1/8

How does it work?

The principle behind finding a fraction of a number, such as 7/8 of 87, is rooted in the method of cross-multiplication.

Consider the following proportion: 7 8 = x 87 (where x represents 7/8 of 87)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 7 × 87 = 8 x
  2. Which gives: 609 = 8 x
  3. Divide both sides by 8 to isolate x: 609 8 = 8 x 8
  4. Which gives the result: 609 8 = x

Thus, 7/8 of 87 is equal to 609/8 (or 76.125 in its decimal form).