Compare 18/21 and 40/15
1st number: 18/21, 2nd number: 2 10/15
18/21 is smaller than 40/15
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
18/21 = 18 × 5/21 × 5 = 90/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
40/15 = 40 × 7/15 × 7 = 280/105 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 90/105 < 280/105 or 18/21 < 40/15
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 40/15 18/21 and 80/15 18/42 and 40/15 18/21 and 40/30 54/21 and 40/15 18/63 and 40/15 18/21 and 40/45 90/21 and 40/15 18/21 and 40/75