Add 21/36 and 3/42
21/36 + 3/42 is 55/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 42 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 42 × 6 = 252,
3/42 = 3 × 6/42 × 6 = 18/252 - Add the two like fractions:
147/252 + 18/252 = 147 + 18/252 = 165/252 - 165/252 simplified gives 55/84
- So, 21/36 + 3/42 = 55/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/36+3/42 21/36+6/42 21/72+3/42 21/36+3/84 63/36+3/42 21/36+9/42 21/36+15/42 21/36+21/42