We divide 644678 by 2
We want to divide 644678 by 2.

Step 1:
If we divide 6 by 2, we get 3 and a remainder of 0.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtract 6 from 6 to get 0.
Take the next digit (4) from the dividend and append it to 0, then repeat: 4 / 2

Step 2:
2 can be fit into 4 2 times, resulting in a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 32.0
The remainder is 0 after subtracting 4 from 4.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 2

Moving on to step 3:
If we divide 4 by 2, we get 2 and a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 322.0
Subtract 4 from 4 to get 0.
Include the next digit (6) from the dividend after 0, then repeat: 6 / 2

On to step 4:
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: 3223.0
Subtracting 6 from 6 leaves us with 0.
Bring next digit (7) of the dividend behind the 0 and repeat the process: 7 / 2

Let's proceed to step 5:
The number 2 fits into 7 3 times, leaving a remainder of 1.
The number 3 becomes the next digit in our result. 
Result so far: 32233.0
Deduct 6 from 7 and we're left with 1.
Fetch the next digit (8) from the dividend, attach it to 1 and continue: 18 / 2

Moving on to step 6:
If we divide 18 by 2, we get 9 and a remainder of 0.
Write down 9 as next digit of the result. 
Result so far: 322339.0
Deduct 18 from 18 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.

Going ahead to step 7:
0 divided by 2 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 322339.0
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.

Going ahead to step 8:
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: 322339.0
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.

Our division results in 322339.0 with a remaining 0.0.