Add 8/21 and 90/72
1st number: 8/21, 2nd number: 1 18/72
8/21 + 90/72 is 137/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 21 × 24 = 504,
8/21 = 8 × 24/21 × 24 = 192/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
90/72 = 90 × 7/72 × 7 = 630/504 - Add the two like fractions:
192/504 + 630/504 = 192 + 630/504 = 822/504 - 822/504 simplified gives 137/84
- So, 8/21 + 90/72 = 137/84
In mixed form: 153/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21+90/72 8/42+90/72 24/21+90/72 8/63+90/72 40/21+90/72 56/21+90/72