Compare 21/45 and 18/20
21/45 is smaller than 18/20
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
18/20 = 18 × 9/20 × 9 = 162/180 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 84/180 < 162/180 or 21/45 < 18/20
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