Add 21/90 and 8/7
1st number: 21/90, 2nd number: 1 1/7
21/90 + 8/7 is 289/210.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 7 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Likewise, for the 2nd fraction, since 7 × 90 = 630,
8/7 = 8 × 90/7 × 90 = 720/630 - Add the two like fractions:
147/630 + 720/630 = 147 + 720/630 = 867/630 - 867/630 simplified gives 289/210
- So, 21/90 + 8/7 = 289/210
In mixed form: 179/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/90+8/7 21/90+16/7 21/90+8/14 63/90+8/7 21/90+24/7 21/90+8/21 21/90+40/7 21/90+8/35 21/90+56/7 21/90+8/49