What is 7/8 of 57?

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 57? We'll show you a straightforward method to achieve that.

How to calculate 7/8 of 57?

  1. Multiply the whole number by the numerator of the fraction: 57 × 7 = 399
  2. Divide this result by denominator of the fraction: 399/8 = 49.875

Since 399/8 is an improper fraction, the result could also be expressed as a mixed number: 49 7/8

How does it work?

The principle behind finding a fraction of a number, such as 7/8 of 57, is rooted in the method of cross-multiplication.

Consider the following proportion: 7 8 = x 57 (where x represents 7/8 of 57)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 7 × 57 = 8 x
  2. Which gives: 399 = 8 x
  3. Divide both sides by 8 to isolate x: 399 8 = 8 x 8
  4. Which gives the result: 399 8 = x

Thus, 7/8 of 57 is equal to 399/8 (or 49.875 in its decimal form).