What is 9/4 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 9/4 of 54? We'll show you a straightforward method to achieve that.

How to calculate 9/4 of 54?

  1. Multiply the whole number by the numerator of the fraction: 54 × 9 = 486
  2. Divide this result by denominator of the fraction: 486/4 = 121.5
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 486/2 = 243
    • 4/2 = 2
  4. Which gives: 243/2

Since 243/2 is an improper fraction, the result could also be expressed as a mixed number: 121 1/2

How does it work?

The principle behind finding a fraction of a number, such as 9/4 of 54, is rooted in the method of cross-multiplication.

Consider the following proportion: 9 4 = x 54 (where x represents 9/4 of 54)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 9 × 54 = 4 x
  2. Which gives: 486 = 4 x
  3. Divide both sides by 4 to isolate x: 486 4 = 4 x 4
  4. Which gives the result: 486 4 = x (or 243 2 = x )

Thus, 9/4 of 54 is equal to 243/2 (or 121.5 in its decimal form).