436509 ÷ 20 
We want to divide 436509 by 20.

Let's proceed to step 1:
20 goes into 4 0 times with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Include the next digit (3) from the dividend after 4, then repeat: 43 / 20

Going ahead to step 2:
When dividing 43 by 20, we get 2 with a remainder of 3.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Deduct 40 from 43 and we're left with 3.
Bring next digit (6) of the dividend behind the 3 and repeat the process: 36 / 20

On to step 3:
When dividing 36 by 20, we get 1 with a remainder of 16.
The next digit of our result is 1. 
Result so far: 21.0
Subtracting 20 from 36 leaves us with 16.
Fetch the next digit (5) from the dividend, attach it to 16 and continue: 165 / 20

Let's proceed to step 4:
The number 20 fits into 165 8 times, leaving a remainder of 5.
Record the quotient 8 as the next digit in the result. 
Result so far: 218.0
Subtract 160 from 165 to get 5.
Fetch the next digit (0) from the dividend, attach it to 5 and continue: 50 / 20

Going ahead to step 5:
The number 20 fits into 50 2 times, leaving a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 2182.0
Subtracting 40 from 50 leaves us with 10.
Grab the next digit (9) from the dividend, add it to 10, then carry on: 109 / 20

Advancing to step 6:
20 goes into 109 5 times with a remainder of 9.
Write down 5 as next digit of the result. 
Result so far: 21825.0
Subtracting 100 from 109 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 7:
20 can be fit into 90 4 times, resulting in a remainder of 10.
Write down 4 as next digit of the result. 
Result so far: 21825.4
Deduct 80 from 90 and we're left 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.

Moving on to step 8:
100 divided by 20 is 5 with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 21825.45
Subtracting 100 from 100 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 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: 21825.45
The remainder is 0 after subtracting 0 from 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 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 21825.45
The remainder is 0 after subtracting 0 from 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 21825.45 with a remainder of 0.0.