Compare 7/21 and 15/40
7/21 is smaller than 15/40
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
7/21 = 7 × 40/21 × 40 = 280/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
15/40 = 15 × 21/40 × 21 = 315/840 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 280/840 < 315/840 or 7/21 < 15/40
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