Add 80/21 and 42/12
1st number: 3 17/21, 2nd number: 3 6/12
80/21 + 42/12 is 307/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
80/21 = 80 × 4/21 × 4 = 320/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
42/12 = 42 × 7/12 × 7 = 294/84 - Add the two like fractions:
320/84 + 294/84 = 320 + 294/84 = 614/84 - 614/84 simplified gives 307/42
- So, 80/21 + 42/12 = 307/42
In mixed form: 713/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21+84/12 80/42+42/12 80/21+42/24 80/63+42/12 80/21+42/36 80/21+42/60 80/21+42/84