Add 21/3 and 90/21
1st number: 7 0/3, 2nd number: 4 6/21
21/3 + 90/21 is 79/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 21 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 3 × 7 = 21,
21/3 = 21 × 7/3 × 7 = 147/21 - Likewise, for the 2nd fraction, since 21 × 1 = 21,
90/21 = 90 × 1/21 × 1 = 90/21 - Add the two like fractions:
147/21 + 90/21 = 147 + 90/21 = 237/21 - 237/21 simplified gives 79/7
- So, 21/3 + 90/21 = 79/7
In mixed form: 112/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/3+90/21 21/6+90/21 21/3+90/42 63/3+90/21 21/9+90/21 21/3+90/63 21/15+90/21