Let's divide 86139 by 20
We want to figure out the number of times 86139 can be divided by 20.

Step 1:
20 can be fit into 8 0 times, resulting in a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Include the next digit (6) from the dividend after 8, then repeat: 86 / 20

Let's proceed to step 2:
20 can be fit into 86 4 times, resulting in a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Deduct 80 from 86 and we're left with 6.
Append the next digit (1) from the dividend to 6 and continue with: 61 / 20

Advancing to step 3:
When dividing 61 by 20, we get 3 with a remainder of 1.
Write down 3 as next digit of the result. 
Result so far: 43.0
If we subtract 60 from 61, we get 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 20

Advancing to step 4:
13 divided by 20 is 0 with a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 430.0
If we subtract 0 from 13, we get 13.
Grab the next digit (9) from the dividend, add it to 13, then carry on: 139 / 20

Moving on to step 5:
If we divide 139 by 20, we get 6 and a remainder of 19.
Write down 6 as next digit of the result. 
Result so far: 4306.0
If we take 120 away from 139, we end up with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 6:
The number 20 fits into 190 9 times, leaving a remainder of 10.
The next digit of our result is 9. 
Result so far: 4306.9
If we take 180 away from 190, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 7:
If we divide 100 by 20, we get 5 and a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 4306.95
Subtract 100 from 100 to 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.

Step 8:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 4306.95
Subtract 0 from 0 to 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.

Moving on to step 9:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 4306.95
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.

In conclusion, the division gives 4306.95 with a balance of 0.0.