644539 ÷ 66 
Our goal is to divide 644539 by 66.

Advancing to step 1:
6 divided by 66 is 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 66

Advancing to step 2:
If we divide 64 by 66, we get 0 and a remainder of 64.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 64, we get 64.
Bring next digit (4) of the dividend behind the 64 and repeat the process: 644 / 66

Moving on to step 3:
When dividing 644 by 66, we get 9 with a remainder of 50.
Write down 9 as next digit of the result. 
Result so far: 9.0
If we take 594 away from 644, we end up with 50.
Take the next digit (5) from the dividend and append it to 50, then repeat: 505 / 66

Let's proceed to step 4:
505 divided by 66 is 7 with a remainder of 43.
The number 7 becomes the next digit in our result. 
Result so far: 97.0
The remainder is 43 after subtracting 462 from 505.
Fetch the next digit (3) from the dividend, attach it to 43 and continue: 433 / 66

Moving on to step 5:
The number 66 fits into 433 6 times, leaving a remainder of 37.
Use 6 as the next digit of our solution. 
Result so far: 976.0
Subtracting 396 from 433 leaves us with 37.
Grab the next digit (9) from the dividend, add it to 37, then carry on: 379 / 66

On to step 6:
If we divide 379 by 66, we get 5 and a remainder of 49.
Write down 5 as next digit of the result. 
Result so far: 9765.0
If we take 330 away from 379, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Step 7:
If we divide 490 by 66, we get 7 and a remainder of 28.
Use 7 as the next digit of our solution. 
Result so far: 9765.7
The remainder is 28 after subtracting 462 from 490.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

On to step 8:
280 divided by 66 is 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 9765.74
If we take 264 away from 280, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 9:
66 goes into 160 2 times with a remainder of 28.
Write down 2 as next digit of the result. 
Result so far: 9765.742
The remainder is 28 after subtracting 132 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 10:
The number 66 fits into 280 4 times, leaving a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 9765.7424
Subtracting 264 from 280 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 11:
66 can be fit into 160 2 times, resulting in a remainder of 28.
Write down 2 as next digit of the result. 
Result so far: 9765.74242
Subtract 132 from 160 to get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Going ahead to step 12:
When dividing 280 by 66, we get 4 with a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 9765.742424
Subtracting 264 from 280 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 13:
If we divide 160 by 66, we get 2 and a remainder of 28.
Use 2 as the next digit of our solution. 
Result so far: 9765.7424242
If we take 132 away from 160, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 14:
66 goes into 280 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 9765.74242424
Subtracting 264 from 280 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final result is 9765.74242424 with a remainder of 1.6e-08.