What is 4/5 of 54?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 4/5 of 54? We'll show you a straightforward method to achieve that.

How to calculate 4/5 of 54?

  1. Multiply the whole number by the numerator of the fraction: 54 × 4 = 216
  2. Divide this result by denominator of the fraction: 216/5 = 43.2

Since 216/5 is an improper fraction, the result could also be expressed as a mixed number: 43 1/5

How does it work?

The principle behind finding a fraction of a number, such as 4/5 of 54, is rooted in the method of cross-multiplication.

Consider the following proportion: 4 5 = x 54 (where x represents 4/5 of 54)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 4 × 54 = 5 x
  2. Which gives: 216 = 5 x
  3. Divide both sides by 5 to isolate x: 216 5 = 5 x 5
  4. Which gives the result: 216 5 = x

Thus, 4/5 of 54 is equal to 216/5 (or 43.2 in its decimal form).