We look at the division of 643966 by 10 
Our goal is to divide 643966 by 10.

Moving on to step 1:
10 can be fit into 6 0 times, resulting in a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 10

On to step 2:
The number 10 fits into 64 6 times, leaving a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 6.0
Subtract 60 from 64 to get 4.
Grab the next digit (3) from the dividend, add it to 4, then carry on: 43 / 10

Moving on to step 3:
If we divide 43 by 10, we get 4 and a remainder of 3.
Record the quotient 4 as the next digit in the result. 
Result so far: 64.0
Deduct 40 from 43 and we're left with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 10

Going ahead to step 4:
39 divided by 10 is 3 with a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 643.0
If we take 30 away from 39, we end up with 9.
Include the next digit (6) from the dividend after 9, then repeat: 96 / 10

Advancing to step 5:
If we divide 96 by 10, we get 9 and a remainder of 6.
The next digit of our result is 9. 
Result so far: 6439.0
Subtracting 90 from 96 leaves us with 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 10

Advancing to step 6:
If we divide 66 by 10, we get 6 and a remainder of 6.
The next digit of our result is 6. 
Result so far: 64396.0
If we subtract 60 from 66, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 7:
When dividing 60 by 10, we get 6 with a remainder of 0.
Write down 6 as next digit of the result. 
Result so far: 64396.6
The remainder is 0 after subtracting 60 from 60.
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 8:
10 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 64396.6
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.

Advancing to step 9:
The number 10 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 64396.6
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.

The quotient of the division is 64396.6, and the remainder is 0.0.