Add 21/40 and 7/9
21/40 + 7/9 is 469/360.
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,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 9 × 40 = 360,
7/9 = 7 × 40/9 × 40 = 280/360 - Add the two like fractions:
189/360 + 280/360 = 189 + 280/360 = 469/360 - So, 21/40 + 7/9 = 469/360
In mixed form: 1109/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+7/9 21/40+14/9 21/80+7/9 21/40+7/18 63/40+7/9 21/40+21/9 21/40+7/27 21/40+35/9 21/40+7/45 21/40+49/9 21/40+7/63