We're dividing 166021 by 87 
The aim is to understand the frequency of 87 in 166021.

Going ahead to step 1:
The number 87 fits into 1 0 times, leaving a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 87

Advancing to step 2:
87 can be fit into 16 0 times, resulting in a remainder of 16.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 16, we get 16.
Append the next digit (6) from the dividend to 16 and continue with: 166 / 87

Advancing to step 3:
When dividing 166 by 87, we get 1 with a remainder of 79.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 87 from 166 leaves us with 79.
Include the next digit (0) from the dividend after 79, then repeat: 790 / 87

Let's proceed to step 4:
790 divided by 87 is 9 with a remainder of 7.
The number 9 becomes the next digit in our result. 
Result so far: 19.0
If we subtract 783 from 790, we get 7.
Append the next digit (2) from the dividend to 7 and continue with: 72 / 87

Step 5:
87 can be fit into 72 0 times, resulting in a remainder of 72.
Record the quotient 0 as the next digit in the result. 
Result so far: 190.0
If we take 0 away from 72, we end up with 72.
Fetch the next digit (1) from the dividend, attach it to 72 and continue: 721 / 87

Moving on to step 6:
87 can be fit into 721 8 times, resulting in a remainder of 25.
Write down 8 as next digit of the result. 
Result so far: 1908.0
The remainder is 25 after subtracting 696 from 721.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Step 7:
250 divided by 87 is 2 with a remainder of 76.
The number 2 becomes the next digit in our result. 
Result so far: 1908.2
If we take 174 away from 250, we end up with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Let's proceed to step 8:
760 divided by 87 is 8 with a remainder of 64.
The number 8 becomes the next digit in our result. 
Result so far: 1908.28
Subtracting 696 from 760 leaves us with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Advancing to step 9:
When dividing 640 by 87, we get 7 with a remainder of 31.
Record the quotient 7 as the next digit in the result. 
Result so far: 1908.287
Subtracting 609 from 640 leaves us with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Advancing to step 10:
310 divided by 87 is 3 with a remainder of 49.
Record the quotient 3 as the next digit in the result. 
Result so far: 1908.2873
The remainder is 49 after subtracting 261 from 310.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Advancing to step 11:
87 can be fit into 490 5 times, resulting in a remainder of 55.
The number 5 becomes the next digit in our result. 
Result so far: 1908.28735
If we subtract 435 from 490, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Advancing to step 12:
87 can be fit into 550 6 times, resulting in a remainder of 28.
The number 6 becomes the next digit in our result. 
Result so far: 1908.287356
If we take 522 away from 550, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Moving on to step 13:
87 can be fit into 280 3 times, resulting in a remainder of 19.
The next digit of our result is 3. 
Result so far: 1908.2873563
The remainder is 19 after subtracting 261 from 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 14:
87 goes into 190 2 times with a remainder of 16.
Put 2 as the next digit of the answer. 
Result so far: 1908.28735632
If we take 174 away from 190, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Our division results in 1908.28735632 with a remaining 1.6e-08.