39963 ÷ 7 = 5709 R0
We're going to perform division on 39963 with 7 as the divisor.

Step 1:
7 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 (9) of the dividend behind the 3 and repeat the process: 39 / 7

Step 2:
7 goes into 39 5 times with a remainder of 4.
Write down 5 as next digit of of the result. 
Result so far: 5
Subtract 35 from 39 to get 4.
Bring next digit (9) of the dividend behind the 4 and repeat the process: 49 / 7

Step 3:
7 goes into 49 7 times with a remainder of 0.
Write down 7 as next digit of of the result. 
Result so far: 57
Subtract 49 from 49 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 7

Step 4:
7 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 570
Subtract 0 from 6 to get 6.
Bring next digit (3) of the dividend behind the 6 and repeat the process: 63 / 7

Step 5:
7 goes into 63 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 5709
Subtract 63 from 63 to get 0.

The final result is 5709 with a remainder of 0.