Compare 42/81 and 21/5
1st number: 42/81, 2nd number: 4 1/5
42/81 is smaller than 21/5
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 5 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 81 × 5 = 405,
42/81 = 42 × 5/81 × 5 = 210/405 - Likewise, for the 2nd fraction, since 5 × 81 = 405,
21/5 = 21 × 81/5 × 81 = 1701/405 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 210/405 < 1701/405 or 42/81 < 21/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/81 and 21/5 42/81 and 42/5 42/81 and 21/10 42/81 and 63/5 42/81 and 21/15 42/81 and 21/25 42/81 and 21/35