Compare 5/8 and 18/21
5/8 is smaller than 18/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
5/8 = 5 × 21/8 × 21 = 105/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
18/21 = 18 × 8/21 × 8 = 144/168 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 105/168 < 144/168 or 5/8 < 18/21
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