We're dividing 390818 by 90 
Let's see how many times 90 fits into 390818.

Going ahead to step 1:
3 divided by 90 is 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 90

Let's proceed to step 2:
When dividing 39 by 90, we get 0 with a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 39 after subtracting 0 from 39.
Take the next digit (0) from the dividend and append it to 39, then repeat: 390 / 90

Let's proceed to step 3:
When dividing 390 by 90, we get 4 with a remainder of 30.
The next digit of our result is 4. 
Result so far: 4.0
Subtracting 360 from 390 leaves us with 30.
Append the next digit (8) from the dividend to 30 and continue with: 308 / 90

Step 4:
308 divided by 90 is 3 with a remainder of 38.
The number 3 becomes the next digit in our result. 
Result so far: 43.0
Deduct 270 from 308 and we're left with 38.
Append the next digit (1) from the dividend to 38 and continue with: 381 / 90

Moving on to step 5:
90 goes into 381 4 times with a remainder of 21.
The number 4 becomes the next digit in our result. 
Result so far: 434.0
If we take 360 away from 381, we end up with 21.
Append the next digit (8) from the dividend to 21 and continue with: 218 / 90

Going ahead to step 6:
90 can be fit into 218 2 times, resulting in a remainder of 38.
The next digit of our result is 2. 
Result so far: 4342.0
The remainder is 38 after subtracting 180 from 218.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Moving on to step 7:
90 goes into 380 4 times with a remainder of 20.
The number 4 becomes the next digit in our result. 
Result so far: 4342.4
Deduct 360 from 380 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 8:
90 goes into 200 2 times with a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 4342.42
Deduct 180 from 200 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 9:
90 goes into 200 2 times with a remainder of 20.
Write down 2 as next digit of the result. 
Result so far: 4342.422
Deduct 180 from 200 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final outcome is 4342.422, with a leftover of 0.002.