Add 21/8 and 42/16
1st number: 2 5/8, 2nd number: 2 10/16
21/8 + 42/16 is 21/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 16 is 16
Next, find the equivalent fraction of both fractional numbers with denominator 16 - For the 1st fraction, since 8 × 2 = 16,
21/8 = 21 × 2/8 × 2 = 42/16 - Likewise, for the 2nd fraction, since 16 × 1 = 16,
42/16 = 42 × 1/16 × 1 = 42/16 - Add the two like fractions:
42/16 + 42/16 = 42 + 42/16 = 84/16 - 84/16 simplified gives 21/4
- So, 21/8 + 42/16 = 21/4
In mixed form: 51/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/8+42/16 21/8+84/16 21/16+42/16 21/8+42/32 63/8+42/16 21/24+42/16 21/8+42/48 21/40+42/16 21/8+42/80 21/56+42/16