Compare 21/18 and 28/20
1st number: 1 3/18, 2nd number: 1 8/20
21/18 is smaller than 28/20
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 18 × 10 = 180,
21/18 = 21 × 10/18 × 10 = 210/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
28/20 = 28 × 9/20 × 9 = 252/180 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 210/180 < 252/180 or 21/18 < 28/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18 and 28/20 21/18 and 56/20 21/36 and 28/20 21/18 and 28/40 63/18 and 28/20 21/18 and 84/20 21/54 and 28/20 21/18 and 28/60 21/90 and 28/20