We divide 851959 by 20
We're looking to find how many times 20 goes into 851959.

Going ahead to step 1:
8 divided by 20 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Append the next digit (5) from the dividend to 8 and continue with: 85 / 20

Moving on to step 2:
20 can be fit into 85 4 times, resulting in a remainder of 5.
The next digit of our result is 4. 
Result so far: 4.0
If we take 80 away from 85, we end up with 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 20

Let's proceed to step 3:
The number 20 fits into 51 2 times, leaving a remainder of 11.
The number 2 becomes the next digit in our result. 
Result so far: 42.0
The remainder is 11 after subtracting 40 from 51.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 20

Let's proceed to step 4:
If we divide 119 by 20, we get 5 and a remainder of 19.
The next digit of our result is 5. 
Result so far: 425.0
Subtracting 100 from 119 leaves us with 19.
Grab the next digit (5) from the dividend, add it to 19, then carry on: 195 / 20

On to step 5:
20 can be fit into 195 9 times, resulting in a remainder of 15.
Record the quotient 9 as the next digit in the result. 
Result so far: 4259.0
Deduct 180 from 195 and we're left with 15.
Fetch the next digit (9) from the dividend, attach it to 15 and continue: 159 / 20

On to step 6:
When dividing 159 by 20, we get 7 with a remainder of 19.
Record the quotient 7 as the next digit in the result. 
Result so far: 42597.0
The remainder is 19 after subtracting 140 from 159.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 7:
20 goes into 190 9 times with a remainder of 10.
The number 9 becomes the next digit in our result. 
Result so far: 42597.9
The remainder is 10 after subtracting 180 from 190.
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 8:
100 divided by 20 is 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 42597.95
The remainder is 0 after subtracting 100 from 100.
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 9:
When dividing 0 by 20, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 42597.95
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.

On to step 10:
20 goes into 0 0 times with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 42597.95
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.

Our division results in 42597.95 with a remaining 0.0.