173543 divided by 18 
The aim is to understand the frequency of 18 in 173543.

Step 1:
If we divide 1 by 18, we get 0 and a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (7) from the dividend to 1 and continue with: 17 / 18

Going ahead to step 2:
When dividing 17 by 18, we get 0 with a remainder of 17.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 17 leaves us with 17.
Fetch the next digit (3) from the dividend, attach it to 17 and continue: 173 / 18

Moving on to step 3:
If we divide 173 by 18, we get 9 and a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 9.0
If we take 162 away from 173, we end up with 11.
Grab the next digit (5) from the dividend, add it to 11, then carry on: 115 / 18

On to step 4:
The number 18 fits into 115 6 times, leaving a remainder of 7.
The number 6 becomes the next digit in our result. 
Result so far: 96.0
Deduct 108 from 115 and we're left with 7.
Fetch the next digit (4) from the dividend, attach it to 7 and continue: 74 / 18

On to step 5:
18 can be fit into 74 4 times, resulting in a remainder of 2.
The next digit of our result is 4. 
Result so far: 964.0
Subtracting 72 from 74 leaves us with 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 18

Let's proceed to step 6:
18 goes into 23 1 times with a remainder of 5.
Write down 1 as next digit of the result. 
Result so far: 9641.0
Subtract 18 from 23 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 7:
18 can be fit into 50 2 times, resulting in a remainder of 14.
Use 2 as the next digit of our solution. 
Result so far: 9641.2
If we subtract 36 from 50, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Let's proceed to step 8:
If we divide 140 by 18, we get 7 and a remainder of 14.
Put 7 as the next digit of the answer. 
Result so far: 9641.27
The remainder is 14 after subtracting 126 from 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 9:
If we divide 140 by 18, we get 7 and a remainder of 14.
Put 7 as the next digit of the answer. 
Result so far: 9641.277
If we take 126 away from 140, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

After the division, we end up with 9641.277 and a remainder of 0.0014.