Add 40/84 and 21/20
1st number: 40/84, 2nd number: 1 1/20
40/84 + 21/20 is 641/420.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
40/84 = 40 × 5/84 × 5 = 200/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420 - Add the two like fractions:
200/420 + 441/420 = 200 + 441/420 = 641/420 - So, 40/84 + 21/20 = 641/420
In mixed form: 1221/420
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/84+21/20 40/84+42/20 40/84+21/40 40/84+63/20 40/84+21/60