Add 28/21 and 12/84
1st number: 1 7/21, 2nd number: 12/84
28/21 + 12/84 is 31/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 84 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
28/21 = 28 × 4/21 × 4 = 112/84 - Likewise, for the 2nd fraction, since 84 × 1 = 84,
12/84 = 12 × 1/84 × 1 = 12/84 - Add the two like fractions:
112/84 + 12/84 = 112 + 12/84 = 124/84 - 124/84 simplified gives 31/21
- So, 28/21 + 12/84 = 31/21
In mixed form: 110/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+12/84 28/21+24/84 28/42+12/84 84/21+12/84 28/21+36/84 28/63+12/84 28/21+60/84