Add 18/12 and 8/21
1st number: 1 6/12, 2nd number: 8/21
18/12 + 8/21 is 79/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
18/12 = 18 × 7/12 × 7 = 126/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
8/21 = 8 × 4/21 × 4 = 32/84 - Add the two like fractions:
126/84 + 32/84 = 126 + 32/84 = 158/84 - 158/84 simplified gives 79/42
- So, 18/12 + 8/21 = 79/42
In mixed form: 137/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/12+8/21 18/12+16/21 18/24+8/21 18/12+8/42 54/12+8/21 18/12+24/21 18/36+8/21 18/12+8/63 90/12+8/21 18/12+40/21 18/60+8/21 18/12+56/21 18/84+8/21