Compare 7/21 and 15/90
7/21 is greater than 15/90
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
7/21 = 7 × 30/21 × 30 = 210/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
15/90 = 15 × 7/90 × 7 = 105/630 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 210/630 > 105/630 or 7/21 > 15/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21 and 15/90 7/21 and 30/90 7/42 and 15/90 7/21 and 45/90 7/63 and 15/90 35/21 and 15/90 7/21 and 75/90 49/21 and 15/90