We look at the division of 645777 by 12 
Let's see how many times 12 fits into 645777.

Advancing to step 1:
12 goes into 6 0 times with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 12

Step 2:
64 divided by 12 is 5 with a remainder of 4.
Put 5 as the next digit of the answer. 
Result so far: 5.0
If we take 60 away from 64, we end up with 4.
Append the next digit (5) from the dividend to 4 and continue with: 45 / 12

On to step 3:
45 divided by 12 is 3 with a remainder of 9.
The next digit of our result is 3. 
Result so far: 53.0
The remainder is 9 after subtracting 36 from 45.
Append the next digit (7) from the dividend to 9 and continue with: 97 / 12

Going ahead to step 4:
The number 12 fits into 97 8 times, leaving a remainder of 1.
The number 8 becomes the next digit in our result. 
Result so far: 538.0
If we subtract 96 from 97, we get 1.
Append the next digit (7) from the dividend to 1 and continue with: 17 / 12

Let's proceed to step 5:
When dividing 17 by 12, we get 1 with a remainder of 5.
The next digit of our result is 1. 
Result so far: 5381.0
Deduct 12 from 17 and we're left with 5.
Take the next digit (7) from the dividend and append it to 5, then repeat: 57 / 12

Advancing to step 6:
The number 12 fits into 57 4 times, leaving a remainder of 9.
Record the quotient 4 as the next digit in the result. 
Result so far: 53814.0
If we subtract 48 from 57, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 7:
12 goes into 90 7 times with a remainder of 6.
Write down 7 as next digit of the result. 
Result so far: 53814.7
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 8:
60 divided by 12 is 5 with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 53814.75
If we take 60 away from 60, 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.

On to step 9:
12 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 53814.75
The remainder is 0 after subtracting 0 from 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 10:
12 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 53814.75
If we subtract 0 from 0, we 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.

The final result is 53814.75 with a remainder of 0.0.