Compare 18/30 and 81/21
1st number: 18/30, 2nd number: 3 18/21
18/30 is smaller than 81/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
18/30 = 18 × 7/30 × 7 = 126/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
81/21 = 81 × 10/21 × 10 = 810/210 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 126/210 < 810/210 or 18/30 < 81/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/30 and 81/21 18/60 and 81/21 18/30 and 81/42 54/30 and 81/21 18/90 and 81/21 18/30 and 81/63 90/30 and 81/21