Add 3/21 and 84/72
1st number: 3/21, 2nd number: 1 12/72
3/21 + 84/72 is 55/42.
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,
3/21 = 3 × 24/21 × 24 = 72/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
84/72 = 84 × 7/72 × 7 = 588/504 - Add the two like fractions:
72/504 + 588/504 = 72 + 588/504 = 660/504 - 660/504 simplified gives 55/42
- So, 3/21 + 84/72 = 55/42
In mixed form: 113/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21+84/72 3/42+84/72 9/21+84/72 3/63+84/72 15/21+84/72