Add 7/8 and 21/81
7/8 + 21/81 is 245/216.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 81 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 8 × 81 = 648,
7/8 = 7 × 81/8 × 81 = 567/648 - Likewise, for the 2nd fraction, since 81 × 8 = 648,
21/81 = 21 × 8/81 × 8 = 168/648 - Add the two like fractions:
567/648 + 168/648 = 567 + 168/648 = 735/648 - 735/648 simplified gives 245/216
- So, 7/8 + 21/81 = 245/216
In mixed form: 129/216
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/8+21/81 7/8+42/81 7/16+21/81 21/8+21/81 7/8+63/81 7/24+21/81 35/8+21/81 7/40+21/81 49/8+21/81 7/56+21/81