Add 21/42 and 84/54
1st number: 21/42, 2nd number: 1 30/54
21/42 + 84/54 is 37/18.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 42 × 9 = 378,
21/42 = 21 × 9/42 × 9 = 189/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
84/54 = 84 × 7/54 × 7 = 588/378 - Add the two like fractions:
189/378 + 588/378 = 189 + 588/378 = 777/378 - 777/378 simplified gives 37/18
- So, 21/42 + 84/54 = 37/18
In mixed form: 21/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/84+84/54 63/42+84/54