Add 21/20 and 9/21
1st number: 1 1/20, 2nd number: 9/21
21/20 + 9/21 is 207/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
9/21 = 9 × 20/21 × 20 = 180/420 - Add the two like fractions:
441/420 + 180/420 = 441 + 180/420 = 621/420 - 621/420 simplified gives 207/140
- So, 21/20 + 9/21 = 207/140
In mixed form: 167/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20+9/21 21/20+18/21 21/40+9/21 21/20+9/42 63/20+9/21 21/20+27/21 21/60+9/21 21/20+9/63 21/20+45/21 21/20+63/21