Add 45/80 and 21/20
1st number: 45/80, 2nd number: 1 1/20
45/80 + 21/20 is 129/80.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 20 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 80 × 1 = 80,
45/80 = 45 × 1/80 × 1 = 45/80 - Likewise, for the 2nd fraction, since 20 × 4 = 80,
21/20 = 21 × 4/20 × 4 = 84/80 - Add the two like fractions:
45/80 + 84/80 = 45 + 84/80 = 129/80 - So, 45/80 + 21/20 = 129/80
In mixed form: 149/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/80+21/20 45/80+42/20 45/80+21/40 45/80+63/20 45/80+21/60