Add 18/15 and 81/20
1st number: 1 3/15, 2nd number: 4 1/20
18/15 + 81/20 is 21/4.
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,
18/15 = 18 × 4/15 × 4 = 72/60 - Likewise, for the 2nd fraction, since 20 × 3 = 60,
81/20 = 81 × 3/20 × 3 = 243/60 - Add the two like fractions:
72/60 + 243/60 = 72 + 243/60 = 315/60 - 315/60 simplified gives 21/4
- So, 18/15 + 81/20 = 21/4
In mixed form: 51/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/15+81/20 18/30+81/20 18/15+81/40 54/15+81/20 18/45+81/20 18/15+81/60 90/15+81/20 18/75+81/20