Add 12/21 and 7/8
12/21 + 7/8 is 81/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
12/21 = 12 × 8/21 × 8 = 96/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
7/8 = 7 × 21/8 × 21 = 147/168 - Add the two like fractions:
96/168 + 147/168 = 96 + 147/168 = 243/168 - 243/168 simplified gives 81/56
- So, 12/21 + 7/8 = 81/56
In mixed form: 125/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21+7/8 12/21+14/8 12/42+7/8 12/21+7/16 36/21+7/8 12/21+21/8 12/63+7/8 12/21+7/24 60/21+7/8 12/21+35/8 12/21+7/40 84/21+7/8 12/21+49/8 12/21+7/56