Add 21/36 and 9/21
21/36 + 9/21 is 85/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 21 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 36 × 7 = 252,
21/36 = 21 × 7/36 × 7 = 147/252 - Likewise, for the 2nd fraction, since 21 × 12 = 252,
9/21 = 9 × 12/21 × 12 = 108/252 - Add the two like fractions:
147/252 + 108/252 = 147 + 108/252 = 255/252 - 255/252 simplified gives 85/84
- So, 21/36 + 9/21 = 85/84
In mixed form: 11/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/36+9/21 21/36+18/21 21/72+9/21 21/36+9/42 63/36+9/21 21/36+27/21 21/36+9/63 21/36+45/21 21/36+63/21