78170 ÷ 20 
We want to figure out the number of times 78170 can be divided by 20.

Let's proceed to step 1:
When dividing 7 by 20, we get 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Take the next digit (8) from the dividend and append it to 7, then repeat: 78 / 20

Advancing to step 2:
The number 20 fits into 78 3 times, leaving a remainder of 18.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtract 60 from 78 to get 18.
Bring next digit (1) of the dividend behind the 18 and repeat the process: 181 / 20

Advancing to step 3:
181 divided by 20 is 9 with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 39.0
The remainder is 1 after subtracting 180 from 181.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 20

Let's proceed to step 4:
20 goes into 17 0 times with a remainder of 17.
Write down 0 as next digit of the result. 
Result so far: 390.0
The remainder is 17 after subtracting 0 from 17.
Grab the next digit (0) from the dividend, add it to 17, then carry on: 170 / 20

Advancing to step 5:
When dividing 170 by 20, we get 8 with a remainder of 10.
Record the quotient 8 as the next digit in the result. 
Result so far: 3908.0
The remainder is 10 after subtracting 160 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 6:
20 can be fit into 100 5 times, resulting in a remainder of 0.
Use 5 as the next digit of our solution. 
Result so far: 3908.5
If we take 100 away from 100, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 7:
If we divide 0 by 20, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 3908.5
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 8:
0 divided by 20 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 3908.5
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 3908.5 with a remainder of 0.0.