Add 21/8 and 28/7
1st number: 2 5/8, 2nd number: 4 0/7
21/8 + 28/7 is 53/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 7 is 56
Next, find the equivalent fraction of both fractional numbers with denominator 56 - For the 1st fraction, since 8 × 7 = 56,
21/8 = 21 × 7/8 × 7 = 147/56 - Likewise, for the 2nd fraction, since 7 × 8 = 56,
28/7 = 28 × 8/7 × 8 = 224/56 - Add the two like fractions:
147/56 + 224/56 = 147 + 224/56 = 371/56 - 371/56 simplified gives 53/8
- So, 21/8 + 28/7 = 53/8
In mixed form: 65/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/8+28/7 21/8+56/7 21/16+28/7 21/8+28/14 63/8+28/7 21/8+84/7 21/24+28/7 21/8+28/21 21/40+28/7 21/8+28/35 21/56+28/7 21/8+28/49