Add 90/21 and 21/9
1st number: 4 6/21, 2nd number: 2 3/9
90/21 + 21/9 is 139/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
90/21 = 90 × 3/21 × 3 = 270/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
21/9 = 21 × 7/9 × 7 = 147/63 - Add the two like fractions:
270/63 + 147/63 = 270 + 147/63 = 417/63 - 417/63 simplified gives 139/21
- So, 90/21 + 21/9 = 139/21
In mixed form: 613/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/21+42/9 90/42+21/9 90/21+21/18 90/21+63/9 90/63+21/9 90/21+21/27 90/21+21/45 90/21+21/63