Add 15/28 and 9/21
15/28 + 9/21 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,
15/28 = 15 × 3/28 × 3 = 45/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
9/21 = 9 × 4/21 × 4 = 36/84 - Add the two like fractions:
45/84 + 36/84 = 45 + 36/84 = 81/84 - 81/84 simplified gives 27/28
- So, 15/28 + 9/21 = 27/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/28+9/21 15/28+18/21 15/56+9/21 15/28+9/42 45/28+9/21 15/28+27/21 15/84+9/21 15/28+9/63 75/28+9/21 15/28+45/21 15/28+63/21