Add 80/12 and 15/21
1st number: 6 8/12, 2nd number: 15/21
80/12 + 15/21 is 155/21.
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,
80/12 = 80 × 7/12 × 7 = 560/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Add the two like fractions:
560/84 + 60/84 = 560 + 60/84 = 620/84 - 620/84 simplified gives 155/21
- So, 80/12 + 15/21 = 155/21
In mixed form: 78/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/12+30/21 80/24+15/21 80/12+15/42 80/12+45/21 80/36+15/21 80/12+15/63 80/12+75/21 80/60+15/21 80/84+15/21