Add 18/9 and 21/15
1st number: 2 0/9, 2nd number: 1 6/15
18/9 + 21/15 is 17/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 15 is 45
Next, find the equivalent fraction of both fractional numbers with denominator 45 - For the 1st fraction, since 9 × 5 = 45,
18/9 = 18 × 5/9 × 5 = 90/45 - Likewise, for the 2nd fraction, since 15 × 3 = 45,
21/15 = 21 × 3/15 × 3 = 63/45 - Add the two like fractions:
90/45 + 63/45 = 90 + 63/45 = 153/45 - 153/45 simplified gives 17/5
- So, 18/9 + 21/15 = 17/5
In mixed form: 32/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/9+21/15 18/9+42/15 18/9+21/30 54/9+21/15 18/9+63/15 18/27+21/15 18/9+21/45 90/9+21/15 18/45+21/15 18/9+21/75 18/63+21/15