What is 4/10 of 43?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 4/10 of 43? We'll show you a straightforward method to achieve that.

How to calculate 4/10 of 43?

  1. Multiply the whole number by the numerator of the fraction: 43 × 4 = 172
  2. Divide this result by denominator of the fraction: 172/10 = 17.2
  3. Simplify by dividing both the numerator and denominator by their GCD (2):
    • 172/2 = 86
    • 10/2 = 5
  4. Which gives: 86/5

Since 86/5 is an improper fraction, the result could also be expressed as a mixed number: 17 1/5

How does it work?

The principle behind finding a fraction of a number, such as 4/10 of 43, is rooted in the method of cross-multiplication.

Consider the following proportion: 4 10 = x 43 (where x represents 4/10 of 43)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 4 × 43 = 10 x
  2. Which gives: 172 = 10 x
  3. Divide both sides by 10 to isolate x: 172 10 = 10 x 10
  4. Which gives the result: 172 10 = x (or 86 5 = x )

Thus, 4/10 of 43 is equal to 86/5 (or 17.2 in its decimal form).