Compare 18/21 and 15/42
18/21 is greater than 15/42
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
18/21 = 18 × 2/21 × 2 = 36/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
15/42 = 15 × 1/42 × 1 = 15/42 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 36/42 > 15/42 or 18/21 > 15/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21 and 15/42 18/21 and 30/42 18/42 and 15/42 18/21 and 15/84 54/21 and 15/42 18/21 and 45/42 18/63 and 15/42 90/21 and 15/42 18/21 and 75/42