Add 18/3 and 21/12
1st number: 6 0/3, 2nd number: 1 9/12
18/3 + 21/12 is 31/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 12 is 12
Next, find the equivalent fraction of both fractional numbers with denominator 12 - For the 1st fraction, since 3 × 4 = 12,
18/3 = 18 × 4/3 × 4 = 72/12 - Likewise, for the 2nd fraction, since 12 × 1 = 12,
21/12 = 21 × 1/12 × 1 = 21/12 - Add the two like fractions:
72/12 + 21/12 = 72 + 21/12 = 93/12 - 93/12 simplified gives 31/4
- So, 18/3 + 21/12 = 31/4
In mixed form: 73/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/3+21/12 18/3+42/12 18/6+21/12 18/3+21/24 54/3+21/12 18/3+63/12 18/9+21/12 18/3+21/36 90/3+21/12 18/15+21/12 18/3+21/60 18/21+21/12 18/3+21/84