We look at the division of 350815 by 90 
We want to figure out the number of times 350815 can be divided by 90.

Let's proceed to step 1:
3 divided by 90 is 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 90

Going ahead to step 2:
When dividing 35 by 90, we get 0 with a remainder of 35.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 35 after subtracting 0 from 35.
Grab the next digit (0) from the dividend, add it to 35, then carry on: 350 / 90

Advancing to step 3:
The number 90 fits into 350 3 times, leaving a remainder of 80.
Use 3 as the next digit of our solution. 
Result so far: 3.0
The remainder is 80 after subtracting 270 from 350.
Fetch the next digit (8) from the dividend, attach it to 80 and continue: 808 / 90

Going ahead to step 4:
If we divide 808 by 90, we get 8 and a remainder of 88.
The number 8 becomes the next digit in our result. 
Result so far: 38.0
If we subtract 720 from 808, we get 88.
Bring next digit (1) of the dividend behind the 88 and repeat the process: 881 / 90

Step 5:
90 goes into 881 9 times with a remainder of 71.
Write down 9 as next digit of the result. 
Result so far: 389.0
Deduct 810 from 881 and we're left with 71.
Include the next digit (5) from the dividend after 71, then repeat: 715 / 90

Advancing to step 6:
When dividing 715 by 90, we get 7 with a remainder of 85.
Write down 7 as next digit of the result. 
Result so far: 3897.0
The remainder is 85 after subtracting 630 from 715.
Since there are no more digits in the dividend, we add a zero to the remainder making it 850, and continue the process.

Moving on to step 7:
The number 90 fits into 850 9 times, leaving a remainder of 40.
Use 9 as the next digit of our solution. 
Result so far: 3897.9
If we take 810 away from 850, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 8:
90 goes into 400 4 times with a remainder of 40.
Write down 4 as next digit of the result. 
Result so far: 3897.94
Subtracting 360 from 400 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 9:
90 can be fit into 400 4 times, resulting in a remainder of 40.
Put 4 as the next digit of the answer. 
Result so far: 3897.944
If we subtract 360 from 400, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The final outcome is 3897.944, with a leftover of 0.004.