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Ratio & proportion tools

How to Simplify Ratios

Simplifying means dividing every part by the same number until nothing is left to divide.

Whole numbers

18:24

  1. Find the greatest common divisor of 18 and 24: it is 6.
  2. Divide both parts: 18 ÷ 6 = 3 and 24 ÷ 6 = 4.
  3. The simplified ratio is 3:4, and 3 and 4 share no divisor above 1.

Decimals

Multiply every part by a power of ten until they are all whole numbers, then simplify as usual. 1.5:2 becomes 15:20, which reduces to 3:4.

Fractions

Put the parts over a common denominator and keep the numerators. 1/2 : 1/3 becomes 3/6 : 2/6, which is 3:2.

Three or more parts

The rule does not change: take the greatest common divisor of all the parts at once. 4:6:10 shares a divisor of 2, giving 2:3:5.