Add 7/21 and 1/90
7/21 + 1/90 is 31/90.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
7/21 = 7 × 30/21 × 30 = 210/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
1/90 = 1 × 7/90 × 7 = 7/630 - Add the two like fractions:
210/630 + 7/630 = 210 + 7/630 = 217/630 - 217/630 simplified gives 31/90
- So, 7/21 + 1/90 = 31/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21+1/90 7/21+2/90 7/42+1/90 7/21+3/90 7/63+1/90 35/21+1/90 7/21+5/90 49/21+1/90 7/21+7/90