Add 21/7 and 42/72
1st number: 3 0/7, 2nd number: 42/72
21/7 + 42/72 is 43/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 7 × 72 = 504,
21/7 = 21 × 72/7 × 72 = 1512/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
42/72 = 42 × 7/72 × 7 = 294/504 - Add the two like fractions:
1512/504 + 294/504 = 1512 + 294/504 = 1806/504 - 1806/504 simplified gives 43/12
- So, 21/7 + 42/72 = 43/12
In mixed form: 37/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7+42/72 21/7+84/72 21/14+42/72 63/7+42/72 21/35+42/72 21/49+42/72