Add 18/9 and 21/42
1st number: 2 0/9, 2nd number: 21/42
18/9 + 21/42 is 5/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 42 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 9 × 14 = 126,
18/9 = 18 × 14/9 × 14 = 252/126 - Likewise, for the 2nd fraction, since 42 × 3 = 126,
21/42 = 21 × 3/42 × 3 = 63/126 - Add the two like fractions:
252/126 + 63/126 = 252 + 63/126 = 315/126 - 315/126 simplified gives 5/2
- So, 18/9 + 21/42 = 5/2
In mixed form: 21/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/9+21/42 18/9+21/84 54/9+21/42 18/9+63/42 18/27+21/42 90/9+21/42 18/45+21/42 18/63+21/42