Add 21/12 and 54/27
1st number: 1 9/12, 2nd number: 2 0/27
21/12 + 54/27 is 15/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 27 is 108
Next, find the equivalent fraction of both fractional numbers with denominator 108 - For the 1st fraction, since 12 × 9 = 108,
21/12 = 21 × 9/12 × 9 = 189/108 - Likewise, for the 2nd fraction, since 27 × 4 = 108,
54/27 = 54 × 4/27 × 4 = 216/108 - Add the two like fractions:
189/108 + 216/108 = 189 + 216/108 = 405/108 - 405/108 simplified gives 15/4
- So, 21/12 + 54/27 = 15/4
In mixed form: 33/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12+54/27 21/24+54/27 63/12+54/27 21/36+54/27 21/12+54/81 21/60+54/27 21/84+54/27