Add 21/40 and 63/8
1st number: 21/40, 2nd number: 7 7/8
21/40 + 63/8 is 42/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 8 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 40 × 1 = 40,
21/40 = 21 × 1/40 × 1 = 21/40 - Likewise, for the 2nd fraction, since 8 × 5 = 40,
63/8 = 63 × 5/8 × 5 = 315/40 - Add the two like fractions:
21/40 + 315/40 = 21 + 315/40 = 336/40 - 336/40 simplified gives 42/5
- So, 21/40 + 63/8 = 42/5
In mixed form: 82/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+63/8 21/80+63/8 21/40+63/16 63/40+63/8 21/40+63/24 21/40+63/40 21/40+63/56