We divide 408642 by 90
We want to figure out the number of times 408642 can be divided by 90.

Advancing to step 1:
4 divided by 90 is 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Include the next digit (0) from the dividend after 4, then repeat: 40 / 90

Advancing to step 2:
90 can be fit into 40 0 times, resulting in a remainder of 40.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 40 leaves us with 40.
Grab the next digit (8) from the dividend, add it to 40, then carry on: 408 / 90

Going ahead to step 3:
When dividing 408 by 90, we get 4 with a remainder of 48.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtracting 360 from 408 leaves us with 48.
Append the next digit (6) from the dividend to 48 and continue with: 486 / 90

Going ahead to step 4:
When dividing 486 by 90, we get 5 with a remainder of 36.
The next digit of our result is 5. 
Result so far: 45.0
The remainder is 36 after subtracting 450 from 486.
Take the next digit (4) from the dividend and append it to 36, then repeat: 364 / 90

Step 5:
90 goes into 364 4 times with a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 454.0
Subtract 360 from 364 to get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 90

Moving on to step 6:
If we divide 42 by 90, we get 0 and a remainder of 42.
Use 0 as the next digit of our solution. 
Result so far: 4540.0
Subtract 0 from 42 to get 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Advancing to step 7:
90 goes into 420 4 times with a remainder of 60.
Record the quotient 4 as the next digit in the result. 
Result so far: 4540.4
If we subtract 360 from 420, we get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Moving on to step 8:
If we divide 600 by 90, we get 6 and a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 4540.46
Subtracting 540 from 600 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 9:
600 divided by 90 is 6 with a remainder of 60.
The next digit of our result is 6. 
Result so far: 4540.466
The remainder is 60 after subtracting 540 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

After the division, we end up with 4540.466 and a remainder of 0.006.