Add 21/81 and 63/28
1st number: 21/81, 2nd number: 2 7/28
21/81 + 63/28 is 271/108.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 28 is 2268
Next, find the equivalent fraction of both fractional numbers with denominator 2268 - For the 1st fraction, since 81 × 28 = 2268,
21/81 = 21 × 28/81 × 28 = 588/2268 - Likewise, for the 2nd fraction, since 28 × 81 = 2268,
63/28 = 63 × 81/28 × 81 = 5103/2268 - Add the two like fractions:
588/2268 + 5103/2268 = 588 + 5103/2268 = 5691/2268 - 5691/2268 simplified gives 271/108
- So, 21/81 + 63/28 = 271/108
In mixed form: 255/108
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/81+63/28 21/81+63/56 63/81+63/28 21/81+63/84