Add 54/15 and 21/28
1st number: 3 9/15, 2nd number: 21/28
54/15 + 21/28 is 87/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 28 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 15 × 28 = 420,
54/15 = 54 × 28/15 × 28 = 1512/420 - Likewise, for the 2nd fraction, since 28 × 15 = 420,
21/28 = 21 × 15/28 × 15 = 315/420 - Add the two like fractions:
1512/420 + 315/420 = 1512 + 315/420 = 1827/420 - 1827/420 simplified gives 87/20
- So, 54/15 + 21/28 = 87/20
In mixed form: 47/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/15+42/28 54/30+21/28 54/15+21/56 54/15+63/28 54/45+21/28 54/15+21/84 54/75+21/28