40086 ÷ 3 = 13362 R0
We're going to perform division on 40086 with 3 as the divisor.

Step 1:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 3 from 4 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 3

Step 2:
3 goes into 10 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 13
Subtract 9 from 10 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 3

Step 3:
3 goes into 10 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 133
Subtract 9 from 10 to get 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 3

Step 4:
3 goes into 18 6 times with a remainder of 0.
Write down 6 as next digit of of the result. 
Result so far: 1336
Subtract 18 from 18 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 3

Step 5:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 13362
Subtract 6 from 6 to get 0.

The final result is 13362 with a remainder of 0.