Add 30/21 and 21/72
1st number: 1 9/21, 2nd number: 21/72
30/21 + 21/72 is 289/168.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 21 × 24 = 504,
30/21 = 30 × 24/21 × 24 = 720/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
21/72 = 21 × 7/72 × 7 = 147/504 - Add the two like fractions:
720/504 + 147/504 = 720 + 147/504 = 867/504 - 867/504 simplified gives 289/168
- So, 30/21 + 21/72 = 289/168
In mixed form: 1121/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/21+21/72 30/21+42/72 30/42+21/72 90/21+21/72 30/21+63/72 30/63+21/72