Add 21/15 and 30/28
1st number: 1 6/15, 2nd number: 1 2/28
21/15 + 30/28 is 173/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 28 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 15 × 28 = 420,
21/15 = 21 × 28/15 × 28 = 588/420 - Likewise, for the 2nd fraction, since 28 × 15 = 420,
30/28 = 30 × 15/28 × 15 = 450/420 - Add the two like fractions:
588/420 + 450/420 = 588 + 450/420 = 1038/420 - 1038/420 simplified gives 173/70
- So, 21/15 + 30/28 = 173/70
In mixed form: 233/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+30/28 21/15+60/28 21/30+30/28 21/15+30/56 63/15+30/28 21/15+90/28 21/45+30/28 21/15+30/84 21/75+30/28