Compare 21/70 and 40/90
21/70 is smaller than 40/90
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 70 × 9 = 630,
21/70 = 21 × 9/70 × 9 = 189/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
40/90 = 40 × 7/90 × 7 = 280/630 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 189/630 < 280/630 or 21/70 < 40/90
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