Add 12/80 and 84/21
1st number: 12/80, 2nd number: 4 0/21
12/80 + 84/21 is 83/20.
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,
84/21 = 84 × 80/21 × 80 = 6720/1680 - Add the two like fractions:
252/1680 + 6720/1680 = 252 + 6720/1680 = 6972/1680 - 6972/1680 simplified gives 83/20
- So, 12/80 + 84/21 = 83/20
In mixed form: 43/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/80+84/21 12/80+84/42 36/80+84/21 12/80+84/63 60/80+84/21 84/80+84/21