644456 ÷ 2 
We want to figure out the number of times 644456 can be divided by 2.

Going ahead to step 1:
The number 2 fits into 6 3 times, leaving a remainder of 0.
Write down 3 as next digit of the result. 
Result so far: 3.0
If we take 6 away from 6, we end up with 0.
Take the next digit (4) from the dividend and append it to 0, then repeat: 4 / 2

Advancing to step 2:
2 goes into 4 2 times with a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 32.0
If we take 4 away from 4, we end up with 0.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 2

Going ahead to step 3:
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: 322.0
Deduct 4 from 4 and we're left with 0.
Grab the next digit (4) from the dividend, add it to 0, then carry on: 4 / 2

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: 3222.0
Deduct 4 from 4 and we're left with 0.
Include the next digit (5) from the dividend after 0, then repeat: 5 / 2

Going ahead to step 5:
If we divide 5 by 2, we get 2 and a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 32222.0
Subtracting 4 from 5 leaves us with 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 2

Step 6:
When dividing 16 by 2, we get 8 with a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 322228.0
Subtract 16 from 16 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.

On to step 7:
0 divided by 2 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 322228.0
If we take 0 away from 0, we end up 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.

Step 8:
When dividing 0 by 2, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 322228.0
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.

Our division results in 322228.0 with a remaining 0.0.