Compare 42/2 and 21/81, Which fraction is greater?

Compare 42/2 and 21/81

1^st number: 21 0/2, 2^nd number: 21/81

42/2 is greater than 21/81

Find the least common denominator or LCM of the two denominators:
LCM of 2 and 81 is 162

Next, find the equivalent fraction of both fractional numbers with denominator 162
For the 1st fraction, since 2 × 81 = 162,
42/2 = 42 × 81/2 × 81 = 3402/162
Likewise, for the 2nd fraction, since 81 × 2 = 162,
21/81 = 21 × 2/81 × 2 = 42/162
Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
3402/162 > 42/162 or 42/2 > 21/81

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad