Add 28/20 and 21/40
1st number: 1 8/20, 2nd number: 21/40
28/20 + 21/40 is 77/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 40 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 20 × 2 = 40,
28/20 = 28 × 2/20 × 2 = 56/40 - Likewise, for the 2nd fraction, since 40 × 1 = 40,
21/40 = 21 × 1/40 × 1 = 21/40 - Add the two like fractions:
56/40 + 21/40 = 56 + 21/40 = 77/40 - So, 28/20 + 21/40 = 77/40
In mixed form: 137/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/20+21/40 28/20+42/40 28/40+21/40 28/20+21/80 84/20+21/40 28/20+63/40 28/60+21/40