Answers

Add 7/21 and 81/20

1^st number: 7/21, 2^nd number: 4 1/20

7/21 + 81/20 is 263/60.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 20 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 21 × 20 = 420,
   7/21 = 7 × 20/21 × 20 = 140/420
3. Likewise, for the 2nd fraction, since 20 × 21 = 420,
   81/20 = 81 × 21/20 × 21 = 1701/420
4. Add the two like fractions:
   140/420 + 1701/420 = 140 + 1701/420 = 1841/420
5. 1841/420 simplified gives 263/60
6. So, 7/21 + 81/20 = 263/60
   In mixed form: 423/60

MathStep (Works offline)

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

Related: ¹⁴/₂₁+⁸¹/₂₀ ⁷/₄₂+⁸¹/₂₀ ⁷/₂₁+⁸¹/₄₀ ⁷/₆₃+⁸¹/₂₀ ⁷/₂₁+⁸¹/₆₀ ³⁵/₂₁+⁸¹/₂₀ ⁴⁹/₂₁+⁸¹/₂₀

Add Fractions Calculator