Add 10/21 and 72/90
10/21 + 72/90 is 134/105.
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,
10/21 = 10 × 30/21 × 30 = 300/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
72/90 = 72 × 7/90 × 7 = 504/630 - Add the two like fractions:
300/630 + 504/630 = 300 + 504/630 = 804/630 - 804/630 simplified gives 134/105
- So, 10/21 + 72/90 = 134/105
In mixed form: 129/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/21+72/90 10/42+72/90 30/21+72/90 10/63+72/90 50/21+72/90 70/21+72/90