Compare 3/12 and 15/21
3/12 is smaller than 15/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 21/84 < 60/84 or 3/12 < 15/21
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