Add 21/12 and 20/18
1st number: 1 9/12, 2nd number: 1 2/18
21/12 + 20/18 is 103/36.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 18 is 36
Next, find the equivalent fraction of both fractional numbers with denominator 36 - For the 1st fraction, since 12 × 3 = 36,
21/12 = 21 × 3/12 × 3 = 63/36 - Likewise, for the 2nd fraction, since 18 × 2 = 36,
20/18 = 20 × 2/18 × 2 = 40/36 - Add the two like fractions:
63/36 + 40/36 = 63 + 40/36 = 103/36 - So, 21/12 + 20/18 = 103/36
In mixed form: 231/36
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12+20/18 21/12+40/18 21/24+20/18 21/12+20/36 63/12+20/18 21/12+60/18 21/36+20/18 21/12+20/54 21/60+20/18 21/12+20/90 21/84+20/18