Add 15/3 and 21/12
1st number: 5 0/3, 2nd number: 1 9/12
15/3 + 21/12 is 27/4.
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,
15/3 = 15 × 4/3 × 4 = 60/12 - Likewise, for the 2nd fraction, since 12 × 1 = 12,
21/12 = 21 × 1/12 × 1 = 21/12 - Add the two like fractions:
60/12 + 21/12 = 60 + 21/12 = 81/12 - 81/12 simplified gives 27/4
- So, 15/3 + 21/12 = 27/4
In mixed form: 63/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/3+21/12 15/3+42/12 15/6+21/12 15/3+21/24 45/3+21/12 15/3+63/12 15/9+21/12 15/3+21/36 75/3+21/12 15/3+21/60 15/21+21/12 15/3+21/84