Add 21/28 and 28/9
1st number: 21/28, 2nd number: 3 1/9
21/28 + 28/9 is 139/36.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 9 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252 - Likewise, for the 2nd fraction, since 9 × 28 = 252,
28/9 = 28 × 28/9 × 28 = 784/252 - Add the two like fractions:
189/252 + 784/252 = 189 + 784/252 = 973/252 - 973/252 simplified gives 139/36
- So, 21/28 + 28/9 = 139/36
In mixed form: 331/36
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+28/9 21/28+56/9 21/56+28/9 21/28+28/18 63/28+28/9 21/28+84/9 21/84+28/9 21/28+28/27 21/28+28/45 21/28+28/63