Add 21/28 and 9/21
21/28 + 9/21 is 33/28.
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,
21/28 = 21 × 3/28 × 3 = 63/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
9/21 = 9 × 4/21 × 4 = 36/84 - Add the two like fractions:
63/84 + 36/84 = 63 + 36/84 = 99/84 - 99/84 simplified gives 33/28
- So, 21/28 + 9/21 = 33/28
In mixed form: 15/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+9/21 21/28+18/21 21/56+9/21 21/28+9/42 63/28+9/21 21/28+27/21 21/84+9/21 21/28+9/63 21/28+45/21 21/28+63/21