Add 72/21 and 90/6
1st number: 3 9/21, 2nd number: 15 0/6
72/21 + 90/6 is 129/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 6 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
72/21 = 72 × 2/21 × 2 = 144/42 - Likewise, for the 2nd fraction, since 6 × 7 = 42,
90/6 = 90 × 7/6 × 7 = 630/42 - Add the two like fractions:
144/42 + 630/42 = 144 + 630/42 = 774/42 - 774/42 simplified gives 129/7
- So, 72/21 + 90/6 = 129/7
In mixed form: 183/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+90/6 72/21+90/12 72/63+90/6 72/21+90/18 72/21+90/30 72/21+90/42