16601509 divided by 231 
The aim is to understand the frequency of 231 in 16601509.

Advancing to step 1:
231 can be fit into 1 0 times, resulting in a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Take the next digit (6) from the dividend and append it to 1, then repeat: 16 / 231

On to step 2:
If we divide 16 by 231, we get 0 and a remainder of 16.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 16 to get 16.
Grab the next digit (6) from the dividend, add it to 16, then carry on: 166 / 231

Moving on to step 3:
When dividing 166 by 231, we get 0 with a remainder of 166.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 166, we end up with 166.
Include the next digit (0) from the dividend after 166, then repeat: 1660 / 231

Let's proceed to step 4:
231 goes into 1660 7 times with a remainder of 43.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Subtract 1617 from 1660 to get 43.
Fetch the next digit (1) from the dividend, attach it to 43 and continue: 431 / 231

Advancing to step 5:
The number 231 fits into 431 1 times, leaving a remainder of 200.
Record the quotient 1 as the next digit in the result. 
Result so far: 71.0
Subtracting 231 from 431 leaves us with 200.
Include the next digit (5) from the dividend after 200, then repeat: 2005 / 231

Let's proceed to step 6:
231 can be fit into 2005 8 times, resulting in a remainder of 157.
The number 8 becomes the next digit in our result. 
Result so far: 718.0
If we subtract 1848 from 2005, we get 157.
Bring next digit (0) of the dividend behind the 157 and repeat the process: 1570 / 231

Moving on to step 7:
231 can be fit into 1570 6 times, resulting in a remainder of 184.
The next digit of our result is 6. 
Result so far: 7186.0
If we subtract 1386 from 1570, we get 184.
Bring next digit (9) of the dividend behind the 184 and repeat the process: 1849 / 231

Going ahead to step 8:
231 goes into 1849 8 times with a remainder of 1.
Write down 8 as next digit of the result. 
Result so far: 71868.0
Subtract 1848 from 1849 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 9:
When dividing 10 by 231, we get 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 71868.0
Subtract 0 from 10 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.

Advancing to step 10:
231 goes into 100 0 times with a remainder of 100.
The next digit of our result is 0. 
Result so far: 71868.0
Subtracting 0 from 100 leaves us with 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Our division results in 71868.0 with a remaining 0.1.