We look at the division of 393249 by 90 
We want to figure out the number of times 393249 can be divided by 90.

Going ahead to step 1:
When dividing 3 by 90, we get 0 with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 90

Going ahead to step 2:
90 goes into 39 0 times with a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 39 to get 39.
Fetch the next digit (3) from the dividend, attach it to 39 and continue: 393 / 90

Going ahead to step 3:
90 goes into 393 4 times with a remainder of 33.
Use 4 as the next digit of our solution. 
Result so far: 4.0
The remainder is 33 after subtracting 360 from 393.
Fetch the next digit (2) from the dividend, attach it to 33 and continue: 332 / 90

On to step 4:
When dividing 332 by 90, we get 3 with a remainder of 62.
The next digit of our result is 3. 
Result so far: 43.0
Deduct 270 from 332 and we're left with 62.
Fetch the next digit (4) from the dividend, attach it to 62 and continue: 624 / 90

Let's proceed to step 5:
If we divide 624 by 90, we get 6 and a remainder of 84.
Use 6 as the next digit of our solution. 
Result so far: 436.0
If we take 540 away from 624, we end up with 84.
Take the next digit (9) from the dividend and append it to 84, then repeat: 849 / 90

On to step 6:
90 can be fit into 849 9 times, resulting in a remainder of 39.
The next digit of our result is 9. 
Result so far: 4369.0
Subtracting 810 from 849 leaves us with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Let's proceed to step 7:
390 divided by 90 is 4 with a remainder of 30.
Record the quotient 4 as the next digit in the result. 
Result so far: 4369.4
Subtracting 360 from 390 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 8:
When dividing 300 by 90, we get 3 with a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 4369.43
The remainder is 30 after subtracting 270 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 9:
The number 90 fits into 300 3 times, leaving a remainder of 30.
Record the quotient 3 as the next digit in the result. 
Result so far: 4369.433
If we take 270 away from 300, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The final result is 4369.433 with a remainder of 0.003.