Add 28/40 and 21/9
1st number: 28/40, 2nd number: 2 3/9
28/40 + 21/9 is 91/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 9 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
28/40 = 28 × 9/40 × 9 = 252/360 - Likewise, for the 2nd fraction, since 9 × 40 = 360,
21/9 = 21 × 40/9 × 40 = 840/360 - Add the two like fractions:
252/360 + 840/360 = 252 + 840/360 = 1092/360 - 1092/360 simplified gives 91/30
- So, 28/40 + 21/9 = 91/30
In mixed form: 31/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40+21/9 28/40+42/9 28/80+21/9 28/40+21/18 84/40+21/9 28/40+63/9 28/40+21/27 28/40+21/45 28/40+21/63