Add 12/80 and 28/21
1st number: 12/80, 2nd number: 1 7/21
12/80 + 28/21 is 89/60.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
12/80 = 12 × 21/80 × 21 = 252/1680 - Likewise, for the 2nd fraction, since 21 × 80 = 1680,
28/21 = 28 × 80/21 × 80 = 2240/1680 - Add the two like fractions:
252/1680 + 2240/1680 = 252 + 2240/1680 = 2492/1680 - 2492/1680 simplified gives 89/60
- So, 12/80 + 28/21 = 89/60
In mixed form: 129/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/80+28/21 12/80+56/21 12/80+28/42 36/80+28/21 12/80+84/21 12/80+28/63 60/80+28/21 84/80+28/21