Add 21/15 and 10/20
1st number: 1 6/15, 2nd number: 10/20
21/15 + 10/20 is 19/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 20 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 15 × 4 = 60,
21/15 = 21 × 4/15 × 4 = 84/60 - Likewise, for the 2nd fraction, since 20 × 3 = 60,
10/20 = 10 × 3/20 × 3 = 30/60 - Add the two like fractions:
84/60 + 30/60 = 84 + 30/60 = 114/60 - 114/60 simplified gives 19/10
- So, 21/15 + 10/20 = 19/10
In mixed form: 19/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+10/20 21/30+10/20 21/15+10/40 63/15+10/20 21/15+30/20 21/45+10/20 21/15+10/60 21/15+50/20 21/75+10/20 21/15+70/20