Add 21/18 and 30/9
1st number: 1 3/18, 2nd number: 3 3/9
21/18 + 30/9 is 9/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 9 is 18
Next, find the equivalent fraction of both fractional numbers with denominator 18 - For the 1st fraction, since 18 × 1 = 18,
21/18 = 21 × 1/18 × 1 = 21/18 - Likewise, for the 2nd fraction, since 9 × 2 = 18,
30/9 = 30 × 2/9 × 2 = 60/18 - Add the two like fractions:
21/18 + 60/18 = 21 + 60/18 = 81/18 - 81/18 simplified gives 9/2
- So, 21/18 + 30/9 = 9/2
In mixed form: 41/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+30/9 21/18+60/9 21/36+30/9 21/18+30/18 63/18+30/9 21/18+90/9 21/54+30/9 21/18+30/27 21/90+30/9 21/18+30/45 21/18+30/63