We look at the division of 867899 by 66 
The aim is to understand the frequency of 66 in 867899.

On to step 1:
66 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 66

On to step 2:
When dividing 86 by 66, we get 1 with a remainder of 20.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 66 from 86, we get 20.
Take the next digit (7) from the dividend and append it to 20, then repeat: 207 / 66

Going ahead to step 3:
When dividing 207 by 66, we get 3 with a remainder of 9.
Put 3 as the next digit of the answer. 
Result so far: 13.0
Deduct 198 from 207 and we're left with 9.
Fetch the next digit (8) from the dividend, attach it to 9 and continue: 98 / 66

Advancing to step 4:
98 divided by 66 is 1 with a remainder of 32.
The next digit of our result is 1. 
Result so far: 131.0
If we subtract 66 from 98, we get 32.
Append the next digit (9) from the dividend to 32 and continue with: 329 / 66

Moving on to step 5:
329 divided by 66 is 4 with a remainder of 65.
The next digit of our result is 4. 
Result so far: 1314.0
If we take 264 away from 329, we end up with 65.
Take the next digit (9) from the dividend and append it to 65, then repeat: 659 / 66

On to step 6:
If we divide 659 by 66, we get 9 and a remainder of 65.
Put 9 as the next digit of the answer. 
Result so far: 13149.0
The remainder is 65 after subtracting 594 from 659.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

On to step 7:
The number 66 fits into 650 9 times, leaving a remainder of 56.
Record the quotient 9 as the next digit in the result. 
Result so far: 13149.9
Deduct 594 from 650 and we're left with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Step 8:
If we divide 560 by 66, we get 8 and a remainder of 32.
Use 8 as the next digit of our solution. 
Result so far: 13149.98
The remainder is 32 after subtracting 528 from 560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Advancing to step 9:
66 can be fit into 320 4 times, resulting in a remainder of 56.
Record the quotient 4 as the next digit in the result. 
Result so far: 13149.984
Deduct 264 from 320 and we're left with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Going ahead to step 10:
560 divided by 66 is 8 with a remainder of 32.
Write down 8 as next digit of the result. 
Result so far: 13149.9848
Subtracting 528 from 560 leaves us with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

On to step 11:
66 can be fit into 320 4 times, resulting in a remainder of 56.
The next digit of our result is 4. 
Result so far: 13149.98484
Subtracting 264 from 320 leaves us with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Advancing to step 12:
The number 66 fits into 560 8 times, leaving a remainder of 32.
Use 8 as the next digit of our solution. 
Result so far: 13149.984848
If we take 528 away from 560, we end up with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Moving on to step 13:
If we divide 320 by 66, we get 4 and a remainder of 56.
The next digit of our result is 4. 
Result so far: 13149.9848484
Subtracting 264 from 320 leaves us with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

On to step 14:
If we divide 560 by 66, we get 8 and a remainder of 32.
Write down 8 as next digit of the result. 
Result so far: 13149.98484848
If we take 528 away from 560, we end up with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

After the division, we end up with 13149.98484848 and a remainder of 3.2e-08.