What is 5/4 of 66?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/4 of 66? We'll show you a straightforward method to achieve that.

How to calculate 5/4 of 66?

  1. Multiply the whole number by the numerator of the fraction: 66 × 5 = 330
  2. Divide this result by denominator of the fraction: 330/4 = 82.5
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 330/2 = 165
    • 4/2 = 2
  4. Which gives: 165/2

Since 165/2 is an improper fraction, the result could also be expressed as a mixed number: 82 1/2

How does it work?

The principle behind finding a fraction of a number, such as 5/4 of 66, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 4 = x 66 (where x represents 5/4 of 66)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 66 = 4 x
  2. Which gives: 330 = 4 x
  3. Divide both sides by 4 to isolate x: 330 4 = 4 x 4
  4. Which gives the result: 330 4 = x (or 165 2 = x )

Thus, 5/4 of 66 is equal to 165/2 (or 82.5 in its decimal form).