Add 12/15 and 21/54
12/15 + 21/54 is 107/90.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 54 is 270
Next, find the equivalent fraction of both fractional numbers with denominator 270 - For the 1st fraction, since 15 × 18 = 270,
12/15 = 12 × 18/15 × 18 = 216/270 - Likewise, for the 2nd fraction, since 54 × 5 = 270,
21/54 = 21 × 5/54 × 5 = 105/270 - Add the two like fractions:
216/270 + 105/270 = 216 + 105/270 = 321/270 - 321/270 simplified gives 107/90
- So, 12/15 + 21/54 = 107/90
In mixed form: 117/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/15+21/54 12/15+42/54 12/30+21/54 36/15+21/54 12/15+63/54 12/45+21/54 60/15+21/54 12/75+21/54 84/15+21/54