Add 18/21 and 27/12
1st number: 18/21, 2nd number: 2 3/12
18/21 + 27/12 is 87/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
18/21 = 18 × 4/21 × 4 = 72/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
27/12 = 27 × 7/12 × 7 = 189/84 - Add the two like fractions:
72/84 + 189/84 = 72 + 189/84 = 261/84 - 261/84 simplified gives 87/28
- So, 18/21 + 27/12 = 87/28
In mixed form: 33/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+27/12 18/21+54/12 18/42+27/12 18/21+27/24 54/21+27/12 18/21+81/12 18/63+27/12 18/21+27/36 90/21+27/12 18/21+27/60 18/21+27/84