Compare 21/81 and 72/84
21/81 is smaller than 72/84
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 84 is 2268
Next, find the equivalent fraction of both fractional numbers with denominator 2268 - For the 1st fraction, since 81 × 28 = 2268,
21/81 = 21 × 28/81 × 28 = 588/2268 - Likewise, for the 2nd fraction, since 84 × 27 = 2268,
72/84 = 72 × 27/84 × 27 = 1944/2268 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 588/2268 < 1944/2268 or 21/81 < 72/84
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