Add 21/28 and 42/18
1st number: 21/28, 2nd number: 2 6/18
21/28 + 42/18 is 37/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 18 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252 - Likewise, for the 2nd fraction, since 18 × 14 = 252,
42/18 = 42 × 14/18 × 14 = 588/252 - Add the two like fractions:
189/252 + 588/252 = 189 + 588/252 = 777/252 - 777/252 simplified gives 37/12
- So, 21/28 + 42/18 = 37/12
In mixed form: 31/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28+42/18 21/28+84/18 21/56+42/18 21/28+42/36 63/28+42/18 21/84+42/18 21/28+42/54 21/28+42/90