Add 21/84 and 56/81
21/84 + 56/81 is 305/324.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 81 is 2268
Next, find the equivalent fraction of both fractional numbers with denominator 2268 - For the 1st fraction, since 84 × 27 = 2268,
21/84 = 21 × 27/84 × 27 = 567/2268 - Likewise, for the 2nd fraction, since 81 × 28 = 2268,
56/81 = 56 × 28/81 × 28 = 1568/2268 - Add the two like fractions:
567/2268 + 1568/2268 = 567 + 1568/2268 = 2135/2268 - 2135/2268 simplified gives 305/324
- So, 21/84 + 56/81 = 305/324
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84+56/81 63/84+56/81