Compare 18/42 and 21/30
18/42 is smaller than 21/30
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 90/210 < 147/210 or 18/42 < 21/30
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