99939 ÷ 5 = 19987 R4
Let's divide 99939 by 5.

Step 1:
5 goes into 9 1 times with a remainder of 4.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 5 from 9 to get 4.
Bring next digit (9) of the dividend behind the 4 and repeat the process: 49 / 5

Step 2:
5 goes into 49 9 times with a remainder of 4.
Write down 9 as next digit of of the result. 
Result so far: 19
Subtract 45 from 49 to get 4.
Bring next digit (9) of the dividend behind the 4 and repeat the process: 49 / 5

Step 3:
5 goes into 49 9 times with a remainder of 4.
Write down 9 as next digit of of the result. 
Result so far: 199
Subtract 45 from 49 to get 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 5

Step 4:
5 goes into 43 8 times with a remainder of 3.
Write down 8 as next digit of of the result. 
Result so far: 1998
Subtract 40 from 43 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 5

Step 5:
5 goes into 39 7 times with a remainder of 4.
Write down 7 as next digit of of the result. 
Result so far: 19987
Subtract 35 from 39 to get 4.

The final result is 19987 with a remainder of 4.