Compare 15/45 and 3/21
15/45 is greater than 3/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
15/45 = 15 × 7/45 × 7 = 105/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
3/21 = 3 × 15/21 × 15 = 45/315 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 105/315 > 45/315 or 15/45 > 3/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/45 and 3/21 15/45 and 6/21 15/90 and 3/21 15/45 and 3/42 15/45 and 9/21 15/45 and 3/63 75/45 and 3/21 15/45 and 15/21