31686 ÷ 8 = 3960 R6
We're going to perform division on 31686 with 8 as the divisor.

Step 1:
8 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 3 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 8

Step 2:
8 goes into 31 3 times with a remainder of 7.
Write down 3 as next digit of of the result. 
Result so far: 3
Subtract 24 from 31 to get 7.
Bring next digit (6) of the dividend behind the 7 and repeat the process: 76 / 8

Step 3:
8 goes into 76 9 times with a remainder of 4.
Write down 9 as next digit of of the result. 
Result so far: 39
Subtract 72 from 76 to get 4.
Bring next digit (8) of the dividend behind the 4 and repeat the process: 48 / 8

Step 4:
8 goes into 48 6 times with a remainder of 0.
Write down 6 as next digit of of the result. 
Result so far: 396
Subtract 48 from 48 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 8

Step 5:
8 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 3960
Subtract 0 from 6 to get 6.

The final result is 3960 with a remainder of 6.