Add 80/21 and 21/40
1st number: 3 17/21, 2nd number: 21/40
80/21 + 21/40 is 3641/840.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
80/21 = 80 × 40/21 × 40 = 3200/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Add the two like fractions:
3200/840 + 441/840 = 3200 + 441/840 = 3641/840 - So, 80/21 + 21/40 = 3641/840
In mixed form: 4281/840
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21+42/40 80/42+21/40 80/21+21/80 80/21+63/40 80/63+21/40