We divide 80019561 by 872
The aim is to understand the frequency of 872 in 80019561.

Step 1:
When dividing 8 by 872, we get 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Fetch the next digit (0) from the dividend, attach it to 8 and continue: 80 / 872

On to step 2:
872 goes into 80 0 times with a remainder of 80.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 80, we end up with 80.
Grab the next digit (0) from the dividend, add it to 80, then carry on: 800 / 872

Advancing to step 3:
872 can be fit into 800 0 times, resulting in a remainder of 800.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 800 leaves us with 800.
Include the next digit (1) from the dividend after 800, then repeat: 8001 / 872

Let's proceed to step 4:
If we divide 8001 by 872, we get 9 and a remainder of 153.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
The remainder is 153 after subtracting 7848 from 8001.
Grab the next digit (9) from the dividend, add it to 153, then carry on: 1539 / 872

Let's proceed to step 5:
When dividing 1539 by 872, we get 1 with a remainder of 667.
Write down 1 as next digit of the result. 
Result so far: 91.0
If we subtract 872 from 1539, we get 667.
Bring next digit (5) of the dividend behind the 667 and repeat the process: 6675 / 872

On to step 6:
The number 872 fits into 6675 7 times, leaving a remainder of 571.
Use 7 as the next digit of our solution. 
Result so far: 917.0
Subtract 6104 from 6675 to get 571.
Bring next digit (6) of the dividend behind the 571 and repeat the process: 5716 / 872

On to step 7:
The number 872 fits into 5716 6 times, leaving a remainder of 484.
Use 6 as the next digit of our solution. 
Result so far: 9176.0
The remainder is 484 after subtracting 5232 from 5716.
Take the next digit (1) from the dividend and append it to 484, then repeat: 4841 / 872

Let's proceed to step 8:
872 can be fit into 4841 5 times, resulting in a remainder of 481.
The number 5 becomes the next digit in our result. 
Result so far: 91765.0
If we take 4360 away from 4841, we end up with 481.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4810, and continue the process.

Going ahead to step 9:
4810 divided by 872 is 5 with a remainder of 450.
The next digit of our result is 5. 
Result so far: 91765.5
If we take 4360 away from 4810, we end up with 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4500, and continue the process.

Moving on to step 10:
872 goes into 4500 5 times with a remainder of 140.
The next digit of our result is 5. 
Result so far: 91765.55
Subtract 4360 from 4500 to get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

After the division, we end up with 91765.55 and a remainder of 0.14.