We're dividing 401567 by 66 
The aim is to understand the frequency of 66 in 401567.

On to step 1:
When dividing 4 by 66, we get 0 with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Include the next digit (0) from the dividend after 4, then repeat: 40 / 66

Let's proceed to step 2:
40 divided by 66 is 0 with a remainder of 40.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 40 leaves us with 40.
Bring next digit (1) of the dividend behind the 40 and repeat the process: 401 / 66

On to step 3:
66 can be fit into 401 6 times, resulting in a remainder of 5.
Write down 6 as next digit of the result. 
Result so far: 6.0
Subtracting 396 from 401 leaves us with 5.
Include the next digit (5) from the dividend after 5, then repeat: 55 / 66

Step 4:
If we divide 55 by 66, we get 0 and a remainder of 55.
The number 0 becomes the next digit in our result. 
Result so far: 60.0
Subtract 0 from 55 to get 55.
Grab the next digit (6) from the dividend, add it to 55, then carry on: 556 / 66

Step 5:
If we divide 556 by 66, we get 8 and a remainder of 28.
Write down 8 as next digit of the result. 
Result so far: 608.0
If we subtract 528 from 556, we get 28.
Include the next digit (7) from the dividend after 28, then repeat: 287 / 66

Advancing to step 6:
The number 66 fits into 287 4 times, leaving a remainder of 23.
The number 4 becomes the next digit in our result. 
Result so far: 6084.0
Subtracting 264 from 287 leaves us with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Advancing to step 7:
The number 66 fits into 230 3 times, leaving a remainder of 32.
Write down 3 as next digit of the result. 
Result so far: 6084.3
Subtracting 198 from 230 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.

Let's proceed to step 8:
66 goes into 320 4 times with a remainder of 56.
Write down 4 as next digit of the result. 
Result so far: 6084.34
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.

Going ahead to step 9:
The number 66 fits into 560 8 times, leaving a remainder of 32.
Record the quotient 8 as the next digit in the result. 
Result so far: 6084.348
Deduct 528 from 560 and we're left 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 10:
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: 6084.3484
If we subtract 264 from 320, we get 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 11:
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: 6084.34848
If we subtract 528 from 560, we get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Step 12:
320 divided by 66 is 4 with a remainder of 56.
Put 4 as the next digit of the answer. 
Result so far: 6084.348484
The remainder is 56 after subtracting 264 from 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Step 13:
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: 6084.3484848
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.

Advancing to step 14:
The number 66 fits into 320 4 times, leaving a remainder of 56.
Put 4 as the next digit of the answer. 
Result so far: 6084.34848484
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.

The final outcome is 6084.34848484, with a leftover of 5.6e-08.