Add 21/18 and 35/21
1st number: 1 3/18, 2nd number: 1 14/21
21/18 + 35/21 is 17/6.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
35/21 = 35 × 6/21 × 6 = 210/126 - Add the two like fractions:
147/126 + 210/126 = 147 + 210/126 = 357/126 - 357/126 simplified gives 17/6
- So, 21/18 + 35/21 = 17/6
In mixed form: 25/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+35/21 21/18+70/21 21/36+35/21 21/18+35/42 63/18+35/21 21/54+35/21 21/18+35/63 21/90+35/21