Add 18/21 and 10/90
18/21 + 10/90 is 61/63.
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,
18/21 = 18 × 30/21 × 30 = 540/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
10/90 = 10 × 7/90 × 7 = 70/630 - Add the two like fractions:
540/630 + 70/630 = 540 + 70/630 = 610/630 - 610/630 simplified gives 61/63
- So, 18/21 + 10/90 = 61/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+10/90 18/21+20/90 18/42+10/90 54/21+10/90 18/21+30/90 18/63+10/90 90/21+10/90 18/21+50/90 18/21+70/90