Add 28/12 and 15/21
1st number: 2 4/12, 2nd number: 15/21
28/12 + 15/21 is 64/21.
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,
28/12 = 28 × 7/12 × 7 = 196/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Add the two like fractions:
196/84 + 60/84 = 196 + 60/84 = 256/84 - 256/84 simplified gives 64/21
- So, 28/12 + 15/21 = 64/21
In mixed form: 31/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/12+15/21 28/12+30/21 28/24+15/21 28/12+15/42 84/12+15/21 28/12+45/21 28/36+15/21 28/12+15/63 28/12+75/21 28/60+15/21 28/84+15/21