We're dividing 666866 by 64 
The aim is to understand the frequency of 64 in 666866.

Advancing to step 1:
The number 64 fits into 6 0 times, leaving a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 64

Advancing to step 2:
When dividing 66 by 64, we get 1 with a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 64 from 66, we get 2.
Include the next digit (6) from the dividend after 2, then repeat: 26 / 64

Let's proceed to step 3:
64 can be fit into 26 0 times, resulting in a remainder of 26.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Subtract 0 from 26 to get 26.
Take the next digit (8) from the dividend and append it to 26, then repeat: 268 / 64

Going ahead to step 4:
268 divided by 64 is 4 with a remainder of 12.
The next digit of our result is 4. 
Result so far: 104.0
Subtract 256 from 268 to get 12.
Append the next digit (6) from the dividend to 12 and continue with: 126 / 64

Let's proceed to step 5:
64 goes into 126 1 times with a remainder of 62.
Use 1 as the next digit of our solution. 
Result so far: 1041.0
If we take 64 away from 126, we end up with 62.
Grab the next digit (6) from the dividend, add it to 62, then carry on: 626 / 64

Moving on to step 6:
64 goes into 626 9 times with a remainder of 50.
The number 9 becomes the next digit in our result. 
Result so far: 10419.0
Subtracting 576 from 626 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Advancing to step 7:
64 can be fit into 500 7 times, resulting in a remainder of 52.
Put 7 as the next digit of the answer. 
Result so far: 10419.7
Subtract 448 from 500 to get 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Advancing to step 8:
64 can be fit into 520 8 times, resulting in a remainder of 8.
Record the quotient 8 as the next digit in the result. 
Result so far: 10419.78
Subtract 512 from 520 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 9:
If we divide 80 by 64, we get 1 and a remainder of 16.
Use 1 as the next digit of our solution. 
Result so far: 10419.781
The remainder is 16 after subtracting 64 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 10:
160 divided by 64 is 2 with a remainder of 32.
The number 2 becomes the next digit in our result. 
Result so far: 10419.7812
Deduct 128 from 160 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.

Advancing to step 11:
64 goes into 320 5 times with a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 10419.78125
Deduct 320 from 320 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 12:
0 divided by 64 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 10419.78125
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 13:
The number 64 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 10419.78125
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 10419.78125, with a leftover of 0.0.