Answers

Add 90/21 and 80/81

1^st number: 4 6/21, 2^nd number: 80/81

90/21 + 80/81 is 2990/567.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 81 is 567
   
   Next, find the equivalent fraction of both fractional numbers with denominator 567
2. For the 1st fraction, since 21 × 27 = 567,
   90/21 = 90 × 27/21 × 27 = 2430/567
3. Likewise, for the 2nd fraction, since 81 × 7 = 567,
   80/81 = 80 × 7/81 × 7 = 560/567
4. Add the two like fractions:
   2430/567 + 560/567 = 2430 + 560/567 = 2990/567
5. So, 90/21 + 80/81 = 2990/567
   In mixed form: 5155/567

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad

Related: ⁹⁰/₄₂+⁸⁰/₈₁ ⁹⁰/₆₃+⁸⁰/₈₁

Add Fractions Calculator