Compare 3/21 and 12/40
3/21 is smaller than 12/40
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,
3/21 = 3 × 40/21 × 40 = 120/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
12/40 = 12 × 21/40 × 21 = 252/840 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 120/840 < 252/840 or 3/21 < 12/40
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