Compare 12/21 and 15/18
12/21 is smaller than 15/18
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
12/21 = 12 × 6/21 × 6 = 72/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 72/126 < 105/126 or 12/21 < 15/18
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