Add 21/15 and 8/20
1st number: 1 6/15, 2nd number: 8/20
21/15 + 8/20 is 9/5.
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,
8/20 = 8 × 3/20 × 3 = 24/60 - Add the two like fractions:
84/60 + 24/60 = 84 + 24/60 = 108/60 - 108/60 simplified gives 9/5
- So, 21/15 + 8/20 = 9/5
In mixed form: 14/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+8/20 21/15+16/20 21/30+8/20 21/15+8/40 63/15+8/20 21/15+24/20 21/45+8/20 21/15+8/60 21/15+40/20 21/75+8/20 21/15+56/20