3866 ÷ 8 = 483 R2
No problem, we've got 3866 and 8 for the division.

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 (8) of the dividend behind the 3 and repeat the process: 38 / 8

Step 2:
8 goes into 38 4 times with a remainder of 6.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 32 from 38 to get 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 8

Step 3:
8 goes into 66 8 times with a remainder of 2.
Write down 8 as next digit of of the result. 
Result so far: 48
Subtract 64 from 66 to get 2.
Bring next digit (6) of the dividend behind the 2 and repeat the process: 26 / 8

Step 4:
8 goes into 26 3 times with a remainder of 2.
Write down 3 as next digit of of the result. 
Result so far: 483
Subtract 24 from 26 to get 2.

The final result is 483 with a remainder of 2.