Compare 15/18 and 12/21
15/18 is greater than 12/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
12/21 = 12 × 6/21 × 6 = 72/126 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 105/126 > 72/126 or 15/18 > 12/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/18 and 12/21 15/18 and 24/21 15/36 and 12/21 15/18 and 12/42 45/18 and 12/21 15/18 and 36/21 15/54 and 12/21 15/18 and 12/63 75/18 and 12/21 15/18 and 60/21 15/90 and 12/21 15/18 and 84/21