81450120 ÷ 181 
The aim is to understand the frequency of 181 in 81450120.

Step 1:
The number 181 fits into 8 0 times, leaving a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Grab the next digit (1) from the dividend, add it to 8, then carry on: 81 / 181

Going ahead to step 2:
The number 181 fits into 81 0 times, leaving a remainder of 81.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 81 leaves us with 81.
Grab the next digit (4) from the dividend, add it to 81, then carry on: 814 / 181

Let's proceed to step 3:
When dividing 814 by 181, we get 4 with a remainder of 90.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtract 724 from 814 to get 90.
Include the next digit (5) from the dividend after 90, then repeat: 905 / 181

Advancing to step 4:
When dividing 905 by 181, we get 5 with a remainder of 0.
Use 5 as the next digit of our solution. 
Result so far: 45.0
If we take 905 away from 905, we end up with 0.
Fetch the next digit (0) from the dividend, attach it to 0 and continue: 0 / 181

Going ahead to step 5:
181 goes into 0 0 times with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 450.0
Subtract 0 from 0 to get 0.
Include the next digit (1) from the dividend after 0, then repeat: 1 / 181

Going ahead to step 6:
When dividing 1 by 181, we get 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 4500.0
Subtract 0 from 1 to get 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 181

Going ahead to step 7:
181 can be fit into 12 0 times, resulting in a remainder of 12.
Use 0 as the next digit of our solution. 
Result so far: 45000.0
Deduct 0 from 12 and we're left with 12.
Grab the next digit (0) from the dividend, add it to 12, then carry on: 120 / 181

Let's proceed to step 8:
If we divide 120 by 181, we get 0 and a remainder of 120.
Write down 0 as next digit of the result. 
Result so far: 450000.0
If we take 0 away from 120, we end up with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 9:
If we divide 1200 by 181, we get 6 and a remainder of 114.
Record the quotient 6 as the next digit in the result. 
Result so far: 450000.6
If we take 1086 away from 1200, we end up with 114.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1140, and continue the process.

Advancing to step 10:
When dividing 1140 by 181, we get 6 with a remainder of 54.
The next digit of our result is 6. 
Result so far: 450000.66
Subtract 1086 from 1140 to get 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

After the division, we end up with 450000.66 and a remainder of 0.054.