We divide 646421 by 2
We want to divide 646421 by 2.

Advancing to step 1:
The number 2 fits into 6 3 times, leaving a remainder of 0.
Use 3 as the next digit of our solution. 
Result so far: 3.0
If we subtract 6 from 6, we get 0.
Append the next digit (4) from the dividend to 0 and continue with: 4 / 2

On to step 2:
The number 2 fits into 4 2 times, leaving a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 32.0
If we take 4 away from 4, we end up with 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 2

Advancing to step 3:
2 can be fit into 6 3 times, resulting in a remainder of 0.
Use 3 as the next digit of our solution. 
Result so far: 323.0
Subtract 6 from 6 to get 0.
Include the next digit (4) from the dividend after 0, then repeat: 4 / 2

Let's proceed to step 4:
When dividing 4 by 2, we get 2 with a remainder of 0.
Record the quotient 2 as the next digit in the result. 
Result so far: 3232.0
The remainder is 0 after subtracting 4 from 4.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 2

Going ahead to step 5:
2 can be fit into 2 1 times, resulting in a remainder of 0.
The next digit of our result is 1. 
Result so far: 32321.0
The remainder is 0 after subtracting 2 from 2.
Fetch the next digit (1) from the dividend, attach it to 0 and continue: 1 / 2

On to step 6:
2 can be fit into 1 0 times, resulting in a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 323210.0
Deduct 0 from 1 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 7:
The number 2 fits into 10 5 times, leaving a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 323210.5
Subtract 10 from 10 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.

Let's proceed to step 8:
2 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 323210.5
Deduct 0 from 0 and we're left 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 2 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 323210.5
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.

In conclusion, the division gives 323210.5 with a balance of 0.0.