Add 18/8 and 21/9
1st number: 2 2/8, 2nd number: 2 3/9
18/8 + 21/9 is 55/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 9 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 8 × 9 = 72,
18/8 = 18 × 9/8 × 9 = 162/72 - Likewise, for the 2nd fraction, since 9 × 8 = 72,
21/9 = 21 × 8/9 × 8 = 168/72 - Add the two like fractions:
162/72 + 168/72 = 162 + 168/72 = 330/72 - 330/72 simplified gives 55/12
- So, 18/8 + 21/9 = 55/12
In mixed form: 47/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/8+21/9 18/8+42/9 18/16+21/9 18/8+21/18 54/8+21/9 18/8+63/9 18/24+21/9 18/8+21/27 90/8+21/9 18/40+21/9 18/8+21/45 18/56+21/9 18/8+21/63