Add 84/21 and 42/12
1st number: 4 0/21, 2nd number: 3 6/12
84/21 + 42/12 is 15/2.
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,
84/21 = 84 × 4/21 × 4 = 336/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
42/12 = 42 × 7/12 × 7 = 294/84 - Add the two like fractions:
336/84 + 294/84 = 336 + 294/84 = 630/84 - 630/84 simplified gives 15/2
- So, 84/21 + 42/12 = 15/2
In mixed form: 71/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21+84/12 84/42+42/12 84/21+42/24 84/63+42/12 84/21+42/36 84/21+42/60 84/21+42/84