Compare 9/15 and 18/21
9/15 is smaller than 18/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
9/15 = 9 × 7/15 × 7 = 63/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
18/21 = 18 × 5/21 × 5 = 90/105 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 63/105 < 90/105 or 9/15 < 18/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/15 and 18/21 9/15 and 36/21 9/30 and 18/21 9/15 and 18/42 27/15 and 18/21 9/15 and 54/21 9/45 and 18/21 9/15 and 18/63 45/15 and 18/21 9/15 and 90/21 9/75 and 18/21 63/15 and 18/21