Compare 21/90 and 20/80
21/90 is smaller than 20/80
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 80 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 90 × 8 = 720,
21/90 = 21 × 8/90 × 8 = 168/720 - Likewise, for the 2nd fraction, since 80 × 9 = 720,
20/80 = 20 × 9/80 × 9 = 180/720 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 168/720 < 180/720 or 21/90 < 20/80
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