We look at the division of 398303 by 90 
Let's see how many times 90 fits into 398303.

On to step 1:
3 divided by 90 is 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 90

Going ahead to step 2:
The number 90 fits into 39 0 times, leaving a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 39, we get 39.
Bring next digit (8) of the dividend behind the 39 and repeat the process: 398 / 90

Advancing to step 3:
When dividing 398 by 90, we get 4 with a remainder of 38.
Use 4 as the next digit of our solution. 
Result so far: 4.0
If we subtract 360 from 398, we get 38.
Take the next digit (3) from the dividend and append it to 38, then repeat: 383 / 90

Moving on to step 4:
The number 90 fits into 383 4 times, leaving a remainder of 23.
Use 4 as the next digit of our solution. 
Result so far: 44.0
If we take 360 away from 383, we end up with 23.
Fetch the next digit (0) from the dividend, attach it to 23 and continue: 230 / 90

On to step 5:
If we divide 230 by 90, we get 2 and a remainder of 50.
The next digit of our result is 2. 
Result so far: 442.0
Deduct 180 from 230 and we're left with 50.
Append the next digit (3) from the dividend to 50 and continue with: 503 / 90

Let's proceed to step 6:
If we divide 503 by 90, we get 5 and a remainder of 53.
Record the quotient 5 as the next digit in the result. 
Result so far: 4425.0
Subtract 450 from 503 to get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Advancing to step 7:
The number 90 fits into 530 5 times, leaving a remainder of 80.
The number 5 becomes the next digit in our result. 
Result so far: 4425.5
Subtract 450 from 530 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.

Advancing to step 8:
800 divided by 90 is 8 with a remainder of 80.
Write down 8 as next digit of the result. 
Result so far: 4425.58
Deduct 720 from 800 and we're left with 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 9:
If we divide 800 by 90, we get 8 and a remainder of 80.
The number 8 becomes the next digit in our result. 
Result so far: 4425.588
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.

Our division results in 4425.588 with a remaining 0.008.