Add 9/12 and 40/21
1st number: 9/12, 2nd number: 1 19/21
9/12 + 40/21 is 223/84.
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,
9/12 = 9 × 7/12 × 7 = 63/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
40/21 = 40 × 4/21 × 4 = 160/84 - Add the two like fractions:
63/84 + 160/84 = 63 + 160/84 = 223/84 - So, 9/12 + 40/21 = 223/84
In mixed form: 255/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/12+40/21 9/12+80/21 9/24+40/21 9/12+40/42 27/12+40/21 9/36+40/21 9/12+40/63 45/12+40/21 9/60+40/21 63/12+40/21 9/84+40/21