Compare 40/90 and 12/21
40/90 is smaller than 12/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
40/90 = 40 × 7/90 × 7 = 280/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
12/21 = 12 × 30/21 × 30 = 360/630 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 280/630 < 360/630 or 40/90 < 12/21
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