53303 ÷ 3 = 17767 R2
Let's divide 53303 by 3.

Step 1:
3 goes into 5 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 3 from 5 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 3

Step 2:
3 goes into 23 7 times with a remainder of 2.
Write down 7 as next digit of of the result. 
Result so far: 17
Subtract 21 from 23 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 3

Step 3:
3 goes into 23 7 times with a remainder of 2.
Write down 7 as next digit of of the result. 
Result so far: 177
Subtract 21 from 23 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: 1776
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: 17767
Subtract 21 from 23 to get 2.

The final result is 17767 with a remainder of 2.