36643 ÷ 3 = 12214 R1
We're going to perform division on 36643 with 3 as the divisor.

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

Step 2:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 12
Subtract 6 from 6 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 3

Step 3:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 122
Subtract 6 from 6 to get 0.
Bring next digit (4) of the dividend behind the 0 and repeat the process: 4 / 3

Step 4:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1221
Subtract 3 from 4 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 3

Step 5:
3 goes into 13 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 12214
Subtract 12 from 13 to get 1.

The final result is 12214 with a remainder of 1.