We look at the division of 170390 by 99 
We want to figure out the number of times 170390 can be divided by 99.

Let's proceed to step 1:
99 goes into 1 0 times with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Include the next digit (7) from the dividend after 1, then repeat: 17 / 99

Step 2:
When dividing 17 by 99, we get 0 with a remainder of 17.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 17 to get 17.
Take the next digit (0) from the dividend and append it to 17, then repeat: 170 / 99

Let's proceed to step 3:
170 divided by 99 is 1 with a remainder of 71.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 99 from 170 and we're left with 71.
Include the next digit (3) from the dividend after 71, then repeat: 713 / 99

Going ahead to step 4:
If we divide 713 by 99, we get 7 and a remainder of 20.
The next digit of our result is 7. 
Result so far: 17.0
Subtract 693 from 713 to get 20.
Include the next digit (9) from the dividend after 20, then repeat: 209 / 99

Step 5:
99 can be fit into 209 2 times, resulting in a remainder of 11.
Put 2 as the next digit of the answer. 
Result so far: 172.0
The remainder is 11 after subtracting 198 from 209.
Include the next digit (0) from the dividend after 11, then repeat: 110 / 99

Moving on to step 6:
If we divide 110 by 99, we get 1 and a remainder of 11.
Write down 1 as next digit of the result. 
Result so far: 1721.0
If we subtract 99 from 110, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 7:
If we divide 110 by 99, we get 1 and a remainder of 11.
The number 1 becomes the next digit in our result. 
Result so far: 1721.1
Subtract 99 from 110 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 8:
When dividing 110 by 99, we get 1 with a remainder of 11.
Write down 1 as next digit of the result. 
Result so far: 1721.11
If we take 99 away from 110, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

After the division, we end up with 1721.11 and a remainder of 0.011.