Add 9/12 and 90/21
1st number: 9/12, 2nd number: 4 6/21
9/12 + 90/21 is 141/28.
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,
90/21 = 90 × 4/21 × 4 = 360/84 - Add the two like fractions:
63/84 + 360/84 = 63 + 360/84 = 423/84 - 423/84 simplified gives 141/28
- So, 9/12 + 90/21 = 141/28
In mixed form: 51/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/12+90/21 9/24+90/21 9/12+90/42 27/12+90/21 9/36+90/21 9/12+90/63 45/12+90/21 9/60+90/21 63/12+90/21 9/84+90/21