What is 3/4 of 28?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 3/4 of 28? We'll show you a straightforward method to achieve that.

How to calculate 3/4 of 28?

  1. Multiply the whole number by the numerator of the fraction: 28 × 3 = 84
  2. Divide this result by denominator of the fraction: 84/4 = 21
  3. Simplify by dividing both the numerator and denominator by their GCD (4):
    • 84/4 = 21
    • 4/4 = 1
  4. Which gives: 21/1

How does it work?

The principle behind finding a fraction of a number, such as 3/4 of 28, is rooted in the method of cross-multiplication.

Consider the following proportion: 3 4 = x 28 (where x represents 3/4 of 28)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 3 × 28 = 4 x
  2. Which gives: 84 = 4 x
  3. Divide both sides by 4 to isolate x: 84 4 = 4 x 4
  4. Which gives the result: 84 4 = x (or 21 1 = x )

Thus, 3/4 of 28 is equal to 21/1 (or 21 in its decimal form).