We look at the division of 450512 by 90 
We want to figure out the number of times 450512 can be divided by 90.

Advancing to step 1:
90 can be fit into 4 0 times, resulting in a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Include the next digit (5) from the dividend after 4, then repeat: 45 / 90

Moving on to step 2:
45 divided by 90 is 0 with a remainder of 45.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 45, we get 45.
Take the next digit (0) from the dividend and append it to 45, then repeat: 450 / 90

Moving on to step 3:
When dividing 450 by 90, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
If we subtract 450 from 450, we get 0.
Append the next digit (5) from the dividend to 0 and continue with: 5 / 90

Let's proceed to step 4:
90 can be fit into 5 0 times, resulting in a remainder of 5.
The next digit of our result is 0. 
Result so far: 50.0
Subtracting 0 from 5 leaves us with 5.
Take the next digit (1) from the dividend and append it to 5, then repeat: 51 / 90

Step 5:
When dividing 51 by 90, we get 0 with a remainder of 51.
Use 0 as the next digit of our solution. 
Result so far: 500.0
Deduct 0 from 51 and we're left with 51.
Bring next digit (2) of the dividend behind the 51 and repeat the process: 512 / 90

Step 6:
If we divide 512 by 90, we get 5 and a remainder of 62.
Use 5 as the next digit of our solution. 
Result so far: 5005.0
Deduct 450 from 512 and we're left with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Let's proceed to step 7:
90 goes into 620 6 times with a remainder of 80.
Record the quotient 6 as the next digit in the result. 
Result so far: 5005.6
If we subtract 540 from 620, we get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Step 8:
90 can be fit into 800 8 times, resulting in a remainder of 80.
Put 8 as the next digit of the answer. 
Result so far: 5005.68
The remainder is 80 after subtracting 720 from 800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Step 9:
If we divide 800 by 90, we get 8 and a remainder of 80.
The next digit of our result is 8. 
Result so far: 5005.688
Subtract 720 from 800 to get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

The final result is 5005.688 with a remainder of 0.008.