Add 70/21 and 45/28
1st number: 3 7/21, 2nd number: 1 17/28
70/21 + 45/28 is 415/84.
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,
45/28 = 45 × 3/28 × 3 = 135/84 - Add the two like fractions:
280/84 + 135/84 = 280 + 135/84 = 415/84 - So, 70/21 + 45/28 = 415/84
In mixed form: 479/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/21+90/28 70/42+45/28 70/21+45/56 70/63+45/28 70/21+45/84