Compare 81/21 and 45/20
1st number: 3 18/21, 2nd number: 2 5/20
81/21 is greater than 45/20
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
81/21 = 81 × 20/21 × 20 = 1620/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
45/20 = 45 × 21/20 × 21 = 945/420 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 1620/420 > 945/420 or 81/21 > 45/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/21 and 90/20 81/42 and 45/20 81/21 and 45/40 81/63 and 45/20 81/21 and 45/60