Add 42/12 and 21/3
1st number: 3 6/12, 2nd number: 7 0/3
42/12 + 21/3 is 21/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 3 is 12
Next, find the equivalent fraction of both fractional numbers with denominator 12 - For the 1st fraction, since 12 × 1 = 12,
42/12 = 42 × 1/12 × 1 = 42/12 - Likewise, for the 2nd fraction, since 3 × 4 = 12,
21/3 = 21 × 4/3 × 4 = 84/12 - Add the two like fractions:
42/12 + 84/12 = 42 + 84/12 = 126/12 - 126/12 simplified gives 21/2
- So, 42/12 + 21/3 = 21/2
In mixed form: 101/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/12+21/3 42/12+42/3 42/24+21/3 42/12+21/6 42/12+63/3 42/36+21/3 42/12+21/9 42/60+21/3 42/12+21/15 42/84+21/3