Add 70/21 and 21/28
1st number: 3 7/21, 2nd number: 21/28
70/21 + 21/28 is 49/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
70/21 = 70 × 4/21 × 4 = 280/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
21/28 = 21 × 3/28 × 3 = 63/84 - Add the two like fractions:
280/84 + 63/84 = 280 + 63/84 = 343/84 - 343/84 simplified gives 49/12
- So, 70/21 + 21/28 = 49/12
In mixed form: 41/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/21+42/28 70/42+21/28 70/21+21/56 70/21+63/28 70/63+21/28 70/21+21/84