What is 9/2 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 9/2 of 45? We'll show you a straightforward method to achieve that.

How to calculate 9/2 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: 405/2 = 202.5

Since 405/2 is an improper fraction, the result could also be expressed as a mixed number: 202 1/2

How does it work?

The principle behind finding a fraction of a number, such as 9/2 of 45, is rooted in the method of cross-multiplication.

Consider the following proportion: 9 2 = x 45 (where x represents 9/2 of 45)

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

Thus, 9/2 of 45 is equal to 405/2 (or 202.5 in its decimal form).