What is 4/7 of 55?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 4/7 of 55? We'll show you a straightforward method to achieve that.

How to calculate 4/7 of 55?

  1. Multiply the whole number by the numerator of the fraction: 55 × 4 = 220
  2. Divide this result by denominator of the fraction: 220/7 = 31.428571428571

Since 220/7 is an improper fraction, the result could also be expressed as a mixed number: 31 3/7

How does it work?

The principle behind finding a fraction of a number, such as 4/7 of 55, is rooted in the method of cross-multiplication.

Consider the following proportion: 4 7 = x 55 (where x represents 4/7 of 55)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 4 × 55 = 7 x
  2. Which gives: 220 = 7 x
  3. Divide both sides by 7 to isolate x: 220 7 = 7 x 7
  4. Which gives the result: 220 7 = x

Thus, 4/7 of 55 is equal to 220/7 (or 31.428571428571 in its decimal form).