Add 90/21 and 15/7
1st number: 4 6/21, 2nd number: 2 1/7
90/21 + 15/7 is 45/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
90/21 = 90 × 1/21 × 1 = 90/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
15/7 = 15 × 3/7 × 3 = 45/21 - Add the two like fractions:
90/21 + 45/21 = 90 + 45/21 = 135/21 - 135/21 simplified gives 45/7
- So, 90/21 + 15/7 = 45/7
In mixed form: 63/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/21+30/7 90/42+15/7 90/21+15/14 90/21+45/7 90/63+15/7 90/21+15/21 90/21+75/7 90/21+15/35 90/21+15/49