What is 8/7 of 31?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 8/7 of 31? We'll show you a straightforward method to achieve that.

How to calculate 8/7 of 31?

  1. Multiply the whole number by the numerator of the fraction: 31 × 8 = 248
  2. Divide this result by denominator of the fraction: 248/7 = 35.428571428571

Since 248/7 is an improper fraction, the result could also be expressed as a mixed number: 35 3/7

How does it work?

The principle behind finding a fraction of a number, such as 8/7 of 31, is rooted in the method of cross-multiplication.

Consider the following proportion: 8 7 = x 31 (where x represents 8/7 of 31)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 8 × 31 = 7 x
  2. Which gives: 248 = 7 x
  3. Divide both sides by 7 to isolate x: 248 7 = 7 x 7
  4. Which gives the result: 248 7 = x

Thus, 8/7 of 31 is equal to 248/7 (or 35.428571428571 in its decimal form).