Compare 21/28 and 81/20
1st number: 21/28, 2nd number: 4 1/20
21/28 is smaller than 81/20
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
21/28 = 21 × 5/28 × 5 = 105/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
81/20 = 81 × 7/20 × 7 = 567/140 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 105/140 < 567/140 or 21/28 < 81/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28 and 81/20 21/56 and 81/20 21/28 and 81/40 63/28 and 81/20 21/84 and 81/20 21/28 and 81/60