Add 21/15 and 56/81
1st number: 1 6/15, 2nd number: 56/81
21/15 + 56/81 is 847/405.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 81 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 15 × 27 = 405,
21/15 = 21 × 27/15 × 27 = 567/405 - Likewise, for the 2nd fraction, since 81 × 5 = 405,
56/81 = 56 × 5/81 × 5 = 280/405 - Add the two like fractions:
567/405 + 280/405 = 567 + 280/405 = 847/405 - So, 21/15 + 56/81 = 847/405
In mixed form: 237/405
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+56/81 21/30+56/81 63/15+56/81 21/45+56/81 21/75+56/81