We look at the division of 50673561 by 18 
The aim is to understand the frequency of 18 in 50673561.

Step 1:
5 divided by 18 is 0 with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 18

On to step 2:
18 goes into 50 2 times with a remainder of 14.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we subtract 36 from 50, we get 14.
Grab the next digit (6) from the dividend, add it to 14, then carry on: 146 / 18

Moving on to step 3:
146 divided by 18 is 8 with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 28.0
Deduct 144 from 146 and we're left with 2.
Append the next digit (7) from the dividend to 2 and continue with: 27 / 18

Going ahead to step 4:
18 goes into 27 1 times with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 281.0
If we subtract 18 from 27, we get 9.
Grab the next digit (3) from the dividend, add it to 9, then carry on: 93 / 18

Going ahead to step 5:
When dividing 93 by 18, we get 5 with a remainder of 3.
Write down 5 as next digit of the result. 
Result so far: 2815.0
Deduct 90 from 93 and we're left with 3.
Grab the next digit (5) from the dividend, add it to 3, then carry on: 35 / 18

Moving on to step 6:
18 goes into 35 1 times with a remainder of 17.
Use 1 as the next digit of our solution. 
Result so far: 28151.0
The remainder is 17 after subtracting 18 from 35.
Grab the next digit (6) from the dividend, add it to 17, then carry on: 176 / 18

Moving on to step 7:
18 goes into 176 9 times with a remainder of 14.
Use 9 as the next digit of our solution. 
Result so far: 281519.0
If we take 162 away from 176, we end up with 14.
Bring next digit (1) of the dividend behind the 14 and repeat the process: 141 / 18

On to step 8:
If we divide 141 by 18, we get 7 and a remainder of 15.
Write down 7 as next digit of the result. 
Result so far: 2815197.0
Subtract 126 from 141 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 9:
18 goes into 150 8 times with a remainder of 6.
Write down 8 as next digit of the result. 
Result so far: 2815197.8
If we take 144 away from 150, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 10:
When dividing 60 by 18, we get 3 with a remainder of 6.
Use 3 as the next digit of our solution. 
Result so far: 2815197.83
Subtract 54 from 60 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 11:
The number 18 fits into 60 3 times, leaving a remainder of 6.
Use 3 as the next digit of our solution. 
Result so far: 2815197.833
If we subtract 54 from 60, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The final outcome is 2815197.833, with a leftover of 0.0006.