Add 3/21 and 9/20
3/21 + 9/20 is 83/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
3/21 = 3 × 20/21 × 20 = 60/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Add the two like fractions:
60/420 + 189/420 = 60 + 189/420 = 249/420 - 249/420 simplified gives 83/140
- So, 3/21 + 9/20 = 83/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21+9/20 3/21+18/20 3/42+9/20 3/21+9/40 9/21+9/20 3/21+27/20 3/63+9/20 3/21+9/60 15/21+9/20 3/21+45/20 3/21+63/20