63803 ÷ 3 = 21267 R2
Let's divide 63803 by 3.

Step 1:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 6 from 6 to get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 3

Step 2:
3 goes into 3 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 21
Subtract 3 from 3 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 3

Step 3:
3 goes into 8 2 times with a remainder of 2.
Write down 2 as next digit of of the result. 
Result so far: 212
Subtract 6 from 8 to get 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 3

Step 4:
3 goes into 20 6 times with a remainder of 2.
Write down 6 as next digit of of the result. 
Result so far: 2126
Subtract 18 from 20 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 3

Step 5:
3 goes into 23 7 times with a remainder of 2.
Write down 7 as next digit of of the result. 
Result so far: 21267
Subtract 21 from 23 to get 2.

The final result is 21267 with a remainder of 2.