Add 12/18 and 84/21
1st number: 12/18, 2nd number: 4 0/21
12/18 + 84/21 is 14/3.
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,
12/18 = 12 × 7/18 × 7 = 84/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
84/21 = 84 × 6/21 × 6 = 504/126 - Add the two like fractions:
84/126 + 504/126 = 84 + 504/126 = 588/126 - 588/126 simplified gives 14/3
- So, 12/18 + 84/21 = 14/3
In mixed form: 42/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/18+84/21 12/36+84/21 12/18+84/42 36/18+84/21 12/54+84/21 12/18+84/63 60/18+84/21 12/90+84/21 84/18+84/21