63900435 ÷ 809 
Our goal is to divide 63900435 by 809.

Moving on to step 1:
The number 809 fits into 6 0 times, leaving a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 809

On to step 2:
When dividing 63 by 809, we get 0 with a remainder of 63.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 63 after subtracting 0 from 63.
Bring next digit (9) of the dividend behind the 63 and repeat the process: 639 / 809

Step 3:
809 can be fit into 639 0 times, resulting in a remainder of 639.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 639, we end up with 639.
Include the next digit (0) from the dividend after 639, then repeat: 6390 / 809

Let's proceed to step 4:
809 goes into 6390 7 times with a remainder of 727.
Write down 7 as next digit of the result. 
Result so far: 7.0
The remainder is 727 after subtracting 5663 from 6390.
Fetch the next digit (0) from the dividend, attach it to 727 and continue: 7270 / 809

Moving on to step 5:
When dividing 7270 by 809, we get 8 with a remainder of 798.
Put 8 as the next digit of the answer. 
Result so far: 78.0
Subtract 6472 from 7270 to get 798.
Grab the next digit (4) from the dividend, add it to 798, then carry on: 7984 / 809

Let's proceed to step 6:
When dividing 7984 by 809, we get 9 with a remainder of 703.
The next digit of our result is 9. 
Result so far: 789.0
If we take 7281 away from 7984, we end up with 703.
Bring next digit (3) of the dividend behind the 703 and repeat the process: 7033 / 809

Let's proceed to step 7:
809 goes into 7033 8 times with a remainder of 561.
The next digit of our result is 8. 
Result so far: 7898.0
If we subtract 6472 from 7033, we get 561.
Take the next digit (5) from the dividend and append it to 561, then repeat: 5615 / 809

Moving on to step 8:
When dividing 5615 by 809, we get 6 with a remainder of 761.
The number 6 becomes the next digit in our result. 
Result so far: 78986.0
If we take 4854 away from 5615, we end up with 761.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7610, and continue the process.

Moving on to step 9:
809 can be fit into 7610 9 times, resulting in a remainder of 329.
Use 9 as the next digit of our solution. 
Result so far: 78986.9
Subtracting 7281 from 7610 leaves us with 329.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3290, and continue the process.

Let's proceed to step 10:
809 can be fit into 3290 4 times, resulting in a remainder of 54.
Record the quotient 4 as the next digit in the result. 
Result so far: 78986.94
If we subtract 3236 from 3290, we get 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Moving on to step 11:
The number 809 fits into 540 0 times, leaving a remainder of 540.
Use 0 as the next digit of our solution. 
Result so far: 78986.94
Subtract 0 from 540 to get 540.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5400, and continue the process.

Let's proceed to step 12:
5400 divided by 809 is 6 with a remainder of 546.
Put 6 as the next digit of the answer. 
Result so far: 78986.9406
Subtract 4854 from 5400 to get 546.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5460, and continue the process.

Step 13:
When dividing 5460 by 809, we get 6 with a remainder of 606.
Write down 6 as next digit of the result. 
Result so far: 78986.94066
If we subtract 4854 from 5460, we get 606.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6060, and continue the process.

The quotient of the division is 78986.94066, and the remainder is 0.000606.