Add 21/18 and 21/9
1st number: 1 3/18, 2nd number: 2 3/9
21/18 + 21/9 is 7/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 9 is 18
Next, find the equivalent fraction of both fractional numbers with denominator 18 - For the 1st fraction, since 18 × 1 = 18,
21/18 = 21 × 1/18 × 1 = 21/18 - Likewise, for the 2nd fraction, since 9 × 2 = 18,
21/9 = 21 × 2/9 × 2 = 42/18 - Add the two like fractions:
21/18 + 42/18 = 21 + 42/18 = 63/18 - 63/18 simplified gives 7/2
- So, 21/18 + 21/9 = 7/2
In mixed form: 31/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+21/9 21/18+42/9 21/36+21/9 21/18+21/18 63/18+21/9 21/18+63/9 21/54+21/9 21/18+21/27 21/90+21/9 21/18+21/45 21/18+21/63