Compare 12/21 and 20/30
12/21 is smaller than 20/30
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
12/21 = 12 × 10/21 × 10 = 120/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
20/30 = 20 × 7/30 × 7 = 140/210 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 120/210 < 140/210 or 12/21 < 20/30
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