Add 21/12 and 9/90
1st number: 1 9/12, 2nd number: 9/90
21/12 + 9/90 is 37/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 90 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 12 × 15 = 180,
21/12 = 21 × 15/12 × 15 = 315/180 - Likewise, for the 2nd fraction, since 90 × 2 = 180,
9/90 = 9 × 2/90 × 2 = 18/180 - Add the two like fractions:
315/180 + 18/180 = 315 + 18/180 = 333/180 - 333/180 simplified gives 37/20
- So, 21/12 + 9/90 = 37/20
In mixed form: 117/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12+9/90 21/12+18/90 21/24+9/90 63/12+9/90 21/12+27/90 21/36+9/90 21/12+45/90 21/60+9/90 21/12+63/90 21/84+9/90