What is 9/3 of 45?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 9/3 of 45? We'll show you a straightforward method to achieve that.

How to calculate 9/3 of 45?

  1. Multiply the whole number by the numerator of the fraction: 45 × 9 = 405
  2. Divide this result by denominator of the fraction: 405/3 = 135
  3. Simplify by dividing both the numerator and denominator by their GCD (3):
    • 405/3 = 135
    • 3/3 = 1
  4. Which gives: 135/1

How does it work?

The principle behind finding a fraction of a number, such as 9/3 of 45, is rooted in the method of cross-multiplication.

Consider the following proportion: 9 3 = x 45 (where x represents 9/3 of 45)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 9 × 45 = 3 x
  2. Which gives: 405 = 3 x
  3. Divide both sides by 3 to isolate x: 405 3 = 3 x 3
  4. Which gives the result: 405 3 = x (or 135 1 = x )

Thus, 9/3 of 45 is equal to 135/1 (or 135 in its decimal form).