We look at the division of 644239 by 9 
We want to figure out the number of times 644239 can be divided by 9.

On to step 1:
9 goes into 6 0 times with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 9

Let's proceed to step 2:
The number 9 fits into 64 7 times, leaving a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
Deduct 63 from 64 and we're left with 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 9

On to step 3:
9 goes into 14 1 times with a remainder of 5.
Use 1 as the next digit of our solution. 
Result so far: 71.0
If we take 9 away from 14, we end up with 5.
Fetch the next digit (2) from the dividend, attach it to 5 and continue: 52 / 9

Going ahead to step 4:
9 can be fit into 52 5 times, resulting in a remainder of 7.
Put 5 as the next digit of the answer. 
Result so far: 715.0
If we take 45 away from 52, we end up with 7.
Bring next digit (3) of the dividend behind the 7 and repeat the process: 73 / 9

Let's proceed to step 5:
When dividing 73 by 9, we get 8 with a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 7158.0
If we subtract 72 from 73, we get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 9

On to step 6:
9 can be fit into 19 2 times, resulting in a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 71582.0
Deduct 18 from 19 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.

Going ahead to step 7:
10 divided by 9 is 1 with a remainder of 1.
Write down 1 as next digit of the result. 
Result so far: 71582.1
The remainder is 1 after subtracting 9 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 8:
If we divide 10 by 9, we get 1 and a remainder of 1.
Write down 1 as next digit of the result. 
Result so far: 71582.11
Deduct 9 from 10 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.

Our division results in 71582.11 with a remaining 0.001.