Answers

Add 21/42 and 70/63

1^st number: 21/42, 2^nd number: 1 7/63

21/42 + 70/63 is 29/18.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 63 is 126
   
   Next, find the equivalent fraction of both fractional numbers with denominator 126
2. For the 1st fraction, since 42 × 3 = 126,
   21/42 = 21 × 3/42 × 3 = 63/126
3. Likewise, for the 2nd fraction, since 63 × 2 = 126,
   70/63 = 70 × 2/63 × 2 = 140/126
4. Add the two like fractions:
   63/126 + 140/126 = 63 + 140/126 = 203/126
5. 203/126 simplified gives 29/18
6. So, 21/42 + 70/63 = 29/18
   In mixed form: 111/18

MathStep (Works offline)

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

Related: ²¹/₈₄+⁷⁰/₆₃ ⁶³/₄₂+⁷⁰/₆₃

Add Fractions Calculator