Compare 18/90 and 21/40
18/90 is smaller than 21/40
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 90 × 4 = 360,
18/90 = 18 × 4/90 × 4 = 72/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 72/360 < 189/360 or 18/90 < 21/40
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