We look at the division of 81874 by 18 
The aim is to understand the frequency of 18 in 81874.

On to step 1:
If we divide 8 by 18, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 18

Moving on to step 2:
When dividing 81 by 18, we get 4 with a remainder of 9.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we subtract 72 from 81, we get 9.
Bring next digit (8) of the dividend behind the 9 and repeat the process: 98 / 18

Moving on to step 3:
18 goes into 98 5 times with a remainder of 8.
The next digit of our result is 5. 
Result so far: 45.0
The remainder is 8 after subtracting 90 from 98.
Grab the next digit (7) from the dividend, add it to 8, then carry on: 87 / 18

Moving on to step 4:
87 divided by 18 is 4 with a remainder of 15.
Record the quotient 4 as the next digit in the result. 
Result so far: 454.0
If we take 72 away from 87, we end up with 15.
Take the next digit (4) from the dividend and append it to 15, then repeat: 154 / 18

Let's proceed to step 5:
18 goes into 154 8 times with a remainder of 10.
The number 8 becomes the next digit in our result. 
Result so far: 4548.0
Subtract 144 from 154 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 6:
100 divided by 18 is 5 with a remainder of 10.
Use 5 as the next digit of our solution. 
Result so far: 4548.5
If we subtract 90 from 100, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
The number 18 fits into 100 5 times, leaving a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 4548.55
If we take 90 away from 100, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final outcome is 4548.55, with a leftover of 0.01.