We're dividing 86958404 by 166 
The aim is to understand the frequency of 166 in 86958404.

Advancing to step 1:
The number 166 fits into 8 0 times, leaving a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Append the next digit (6) from the dividend to 8 and continue with: 86 / 166

Going ahead to step 2:
86 divided by 166 is 0 with a remainder of 86.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 86 and we're left with 86.
Fetch the next digit (9) from the dividend, attach it to 86 and continue: 869 / 166

On to step 3:
166 goes into 869 5 times with a remainder of 39.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Subtract 830 from 869 to get 39.
Fetch the next digit (5) from the dividend, attach it to 39 and continue: 395 / 166

Advancing to step 4:
395 divided by 166 is 2 with a remainder of 63.
The next digit of our result is 2. 
Result so far: 52.0
Subtract 332 from 395 to get 63.
Bring next digit (8) of the dividend behind the 63 and repeat the process: 638 / 166

Step 5:
166 can be fit into 638 3 times, resulting in a remainder of 140.
Put 3 as the next digit of the answer. 
Result so far: 523.0
The remainder is 140 after subtracting 498 from 638.
Take the next digit (4) from the dividend and append it to 140, then repeat: 1404 / 166

Going ahead to step 6:
The number 166 fits into 1404 8 times, leaving a remainder of 76.
Write down 8 as next digit of the result. 
Result so far: 5238.0
Subtracting 1328 from 1404 leaves us with 76.
Grab the next digit (0) from the dividend, add it to 76, then carry on: 760 / 166

Let's proceed to step 7:
If we divide 760 by 166, we get 4 and a remainder of 96.
Write down 4 as next digit of the result. 
Result so far: 52384.0
Deduct 664 from 760 and we're left with 96.
Grab the next digit (4) from the dividend, add it to 96, then carry on: 964 / 166

Let's proceed to step 8:
The number 166 fits into 964 5 times, leaving a remainder of 134.
Use 5 as the next digit of our solution. 
Result so far: 523845.0
The remainder is 134 after subtracting 830 from 964.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1340, and continue the process.

Advancing to step 9:
166 can be fit into 1340 8 times, resulting in a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 523845.8
Subtracting 1328 from 1340 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 10:
166 can be fit into 120 0 times, resulting in a remainder of 120.
Put 0 as the next digit of the answer. 
Result so far: 523845.8
The remainder is 120 after subtracting 0 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

On to step 11:
The number 166 fits into 1200 7 times, leaving a remainder of 38.
Put 7 as the next digit of the answer. 
Result so far: 523845.807
Deduct 1162 from 1200 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Moving on to step 12:
380 divided by 166 is 2 with a remainder of 48.
The number 2 becomes the next digit in our result. 
Result so far: 523845.8072
If we subtract 332 from 380, we get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Step 13:
When dividing 480 by 166, we get 2 with a remainder of 148.
Put 2 as the next digit of the answer. 
Result so far: 523845.80722
Deduct 332 from 480 and we're left with 148.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1480, and continue the process.

In conclusion, the division gives 523845.80722 with a balance of 0.000148.