We look at the division of 42819131 by 18 
The aim is to understand the frequency of 18 in 42819131.

Let's proceed to step 1:
When dividing 4 by 18, we get 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 18

Advancing to step 2:
18 can be fit into 42 2 times, resulting in a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
The remainder is 6 after subtracting 36 from 42.
Grab the next digit (8) from the dividend, add it to 6, then carry on: 68 / 18

Going ahead to step 3:
18 goes into 68 3 times with a remainder of 14.
The next digit of our result is 3. 
Result so far: 23.0
Subtracting 54 from 68 leaves us with 14.
Append the next digit (1) from the dividend to 14 and continue with: 141 / 18

Advancing to step 4:
18 can be fit into 141 7 times, resulting in a remainder of 15.
The next digit of our result is 7. 
Result so far: 237.0
If we subtract 126 from 141, we get 15.
Grab the next digit (9) from the dividend, add it to 15, then carry on: 159 / 18

Advancing to step 5:
18 goes into 159 8 times with a remainder of 15.
The next digit of our result is 8. 
Result so far: 2378.0
If we take 144 away from 159, we end up with 15.
Bring next digit (1) of the dividend behind the 15 and repeat the process: 151 / 18

Let's proceed to step 6:
If we divide 151 by 18, we get 8 and a remainder of 7.
Write down 8 as next digit of the result. 
Result so far: 23788.0
Subtracting 144 from 151 leaves us with 7.
Include the next digit (3) from the dividend after 7, then repeat: 73 / 18

Let's proceed to step 7:
The number 18 fits into 73 4 times, leaving a remainder of 1.
Put 4 as the next digit of the answer. 
Result so far: 237884.0
If we subtract 72 from 73, we get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 18

Step 8:
11 divided by 18 is 0 with a remainder of 11.
The number 0 becomes the next digit in our result. 
Result so far: 2378840.0
If we take 0 away from 11, 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.

Step 9:
18 goes into 110 6 times with a remainder of 2.
Record the quotient 6 as the next digit in the result. 
Result so far: 2378840.6
Subtract 108 from 110 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 10:
When dividing 20 by 18, we get 1 with a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 2378840.61
If we take 18 away from 20, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 11:
When dividing 20 by 18, we get 1 with a remainder of 2.
Record the quotient 1 as the next digit in the result. 
Result so far: 2378840.611
Subtract 18 from 20 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final outcome is 2378840.611, with a leftover of 0.0002.