645430 ÷ 12 
We want to figure out the number of times 645430 can be divided by 12.

Going ahead to step 1:
When dividing 6 by 12, we get 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 12

Let's proceed to step 2:
12 goes into 64 5 times with a remainder of 4.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
Deduct 60 from 64 and we're left with 4.
Grab the next digit (5) from the dividend, add it to 4, then carry on: 45 / 12

Moving 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
Subtracting 36 from 45 leaves us with 9.
Grab the next digit (4) from the dividend, add it to 9, then carry on: 94 / 12

Step 4:
When dividing 94 by 12, we get 7 with a remainder of 10.
The next digit of our result is 7. 
Result so far: 537.0
Subtracting 84 from 94 leaves us with 10.
Grab the next digit (3) from the dividend, add it to 10, then carry on: 103 / 12

Going ahead to step 5:
When dividing 103 by 12, we get 8 with a remainder of 7.
Write down 8 as next digit of the result. 
Result so far: 5378.0
Deduct 96 from 103 and we're left with 7.
Take the next digit (0) from the dividend and append it to 7, then repeat: 70 / 12

Moving on to step 6:
The number 12 fits into 70 5 times, leaving a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 53785.0
The remainder is 10 after subtracting 60 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 7:
100 divided by 12 is 8 with a remainder of 4.
The next digit of our result is 8. 
Result so far: 53785.8
Deduct 96 from 100 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 8:
When dividing 40 by 12, we get 3 with a remainder of 4.
Record the quotient 3 as the next digit in the result. 
Result so far: 53785.83
Subtracting 36 from 40 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 9:
12 goes into 40 3 times with a remainder of 4.
Write down 3 as next digit of the result. 
Result so far: 53785.833
The remainder is 4 after subtracting 36 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The quotient of the division is 53785.833, and the remainder is 0.0004.