78309 ÷ 5 = 15661 R4
Let's divide 78309 by 5.

Step 1:
5 goes into 7 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 5 from 7 to get 2.
Bring next digit (8) of the dividend behind the 2 and repeat the process: 28 / 5

Step 2:
5 goes into 28 5 times with a remainder of 3.
Write down 5 as next digit of of the result. 
Result so far: 15
Subtract 25 from 28 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 5

Step 3:
5 goes into 33 6 times with a remainder of 3.
Write down 6 as next digit of of the result. 
Result so far: 156
Subtract 30 from 33 to get 3.
Bring next digit (0) of the dividend behind the 3 and repeat the process: 30 / 5

Step 4:
5 goes into 30 6 times with a remainder of 0.
Write down 6 as next digit of of the result. 
Result so far: 1566
Subtract 30 from 30 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 5

Step 5:
5 goes into 9 1 times with a remainder of 4.
Write down 1 as next digit of of the result. 
Result so far: 15661
Subtract 5 from 9 to get 4.

The final result is 15661 with a remainder of 4.