Add 21/3 and 12/15
1st number: 7 0/3, 2nd number: 12/15
21/3 + 12/15 is 39/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 15 is 15
Next, find the equivalent fraction of both fractional numbers with denominator 15 - For the 1st fraction, since 3 × 5 = 15,
21/3 = 21 × 5/3 × 5 = 105/15 - Likewise, for the 2nd fraction, since 15 × 1 = 15,
12/15 = 12 × 1/15 × 1 = 12/15 - Add the two like fractions:
105/15 + 12/15 = 105 + 12/15 = 117/15 - 117/15 simplified gives 39/5
- So, 21/3 + 12/15 = 39/5
In mixed form: 74/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/3+12/15 21/3+24/15 21/6+12/15 21/3+12/30 63/3+12/15 21/3+36/15 21/9+12/15 21/3+12/45 21/3+60/15 21/15+12/15 21/3+12/75 21/3+84/15