Add 28/36 and 21/81
28/36 + 21/81 is 28/27.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 81 is 324
Next, find the equivalent fraction of both fractional numbers with denominator 324 - For the 1st fraction, since 36 × 9 = 324,
28/36 = 28 × 9/36 × 9 = 252/324 - Likewise, for the 2nd fraction, since 81 × 4 = 324,
21/81 = 21 × 4/81 × 4 = 84/324 - Add the two like fractions:
252/324 + 84/324 = 252 + 84/324 = 336/324 - 336/324 simplified gives 28/27
- So, 28/36 + 21/81 = 28/27
In mixed form: 11/27
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/36+21/81 28/36+42/81 28/72+21/81 84/36+21/81 28/36+63/81