Let's divide 39243 by 90
We want to figure out the number of times 39243 can be divided by 90.

Moving on to step 1:
90 can be fit into 3 0 times, resulting in a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 90

On to step 2:
If we divide 39 by 90, we get 0 and a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 39 after subtracting 0 from 39.
Fetch the next digit (2) from the dividend, attach it to 39 and continue: 392 / 90

Let's proceed to step 3:
90 goes into 392 4 times with a remainder of 32.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we subtract 360 from 392, we get 32.
Fetch the next digit (4) from the dividend, attach it to 32 and continue: 324 / 90

Going ahead to step 4:
324 divided by 90 is 3 with a remainder of 54.
Put 3 as the next digit of the answer. 
Result so far: 43.0
Subtracting 270 from 324 leaves us with 54.
Grab the next digit (3) from the dividend, add it to 54, then carry on: 543 / 90

On to step 5:
When dividing 543 by 90, we get 6 with a remainder of 3.
Write down 6 as next digit of the result. 
Result so far: 436.0
Deduct 540 from 543 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 6:
30 divided by 90 is 0 with a remainder of 30.
The next digit of our result is 0. 
Result so far: 436.0
The remainder is 30 after subtracting 0 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 7:
When dividing 300 by 90, we get 3 with a remainder of 30.
Write down 3 as next digit of the result. 
Result so far: 436.03
Deduct 270 from 300 and we're left 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.

Step 8:
If we divide 300 by 90, we get 3 and a remainder of 30.
Write down 3 as next digit of the result. 
Result so far: 436.033
Deduct 270 from 300 and we're left 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 436.033 with a remainder of 0.003.