Add 7/28 and 15/21
7/28 + 15/21 is 27/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
7/28 = 7 × 3/28 × 3 = 21/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Add the two like fractions:
21/84 + 60/84 = 21 + 60/84 = 81/84 - 81/84 simplified gives 27/28
- So, 7/28 + 15/21 = 27/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/28+15/21 7/28+30/21 7/56+15/21 7/28+15/42 21/28+15/21 7/28+45/21 7/84+15/21 7/28+15/63 35/28+15/21 7/28+75/21 49/28+15/21