3990 ÷ 1 = 3990 R0
No problem, we've got 3990 and 1 for the division.

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

Step 2:
1 goes into 9 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 39
Subtract 9 from 9 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 1

Step 3:
1 goes into 9 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 399
Subtract 9 from 9 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 1

Step 4:
1 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 3990
Subtract 0 from 0 to get 0.

The final result is 3990 with a remainder of 0.