857398 ÷ 90 
Our goal is to divide 857398 by 90.

Advancing to step 1:
The number 90 fits into 8 0 times, leaving a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (5) from the dividend, add it to 8, then carry on: 85 / 90

Advancing to step 2:
85 divided by 90 is 0 with a remainder of 85.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 85, we end up with 85.
Bring next digit (7) of the dividend behind the 85 and repeat the process: 857 / 90

Going ahead to step 3:
If we divide 857 by 90, we get 9 and a remainder of 47.
Use 9 as the next digit of our solution. 
Result so far: 9.0
If we take 810 away from 857, we end up with 47.
Bring next digit (3) of the dividend behind the 47 and repeat the process: 473 / 90

Moving on to step 4:
When dividing 473 by 90, we get 5 with a remainder of 23.
The next digit of our result is 5. 
Result so far: 95.0
Subtract 450 from 473 to get 23.
Bring next digit (9) of the dividend behind the 23 and repeat the process: 239 / 90

Step 5:
90 goes into 239 2 times with a remainder of 59.
The next digit of our result is 2. 
Result so far: 952.0
Subtract 180 from 239 to get 59.
Grab the next digit (8) from the dividend, add it to 59, then carry on: 598 / 90

Advancing to step 6:
The number 90 fits into 598 6 times, leaving a remainder of 58.
Record the quotient 6 as the next digit in the result. 
Result so far: 9526.0
If we take 540 away from 598, we end up with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Let's proceed to step 7:
90 can be fit into 580 6 times, resulting in a remainder of 40.
The next digit of our result is 6. 
Result so far: 9526.6
The remainder is 40 after subtracting 540 from 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 8:
400 divided by 90 is 4 with a remainder of 40.
Write down 4 as next digit of the result. 
Result so far: 9526.64
Subtract 360 from 400 to 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.

Let's proceed to step 9:
90 goes into 400 4 times with a remainder of 40.
The next digit of our result is 4. 
Result so far: 9526.644
Subtract 360 from 400 to 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 9526.644, with a leftover of 0.004.