Add 81/12 and 2/21
1st number: 6 9/12, 2nd number: 2/21
81/12 + 2/21 is 575/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
81/12 = 81 × 7/12 × 7 = 567/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
2/21 = 2 × 4/21 × 4 = 8/84 - Add the two like fractions:
567/84 + 8/84 = 567 + 8/84 = 575/84 - So, 81/12 + 2/21 = 575/84
In mixed form: 671/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/12+4/21 81/24+2/21 81/12+2/42 81/12+6/21 81/36+2/21 81/12+2/63 81/12+10/21 81/60+2/21 81/12+14/21 81/84+2/21