Compare 3/90 and 20/21
3/90 is smaller than 20/21
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
3/90 = 3 × 7/90 × 7 = 21/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
20/21 = 20 × 30/21 × 30 = 600/630 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 21/630 < 600/630 or 3/90 < 20/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/90 and 20/21 3/90 and 40/21 3/90 and 20/42 9/90 and 20/21 3/90 and 60/21 3/90 and 20/63 15/90 and 20/21 21/90 and 20/21