We look at the division of 2546417 by 666 
The aim is to understand the frequency of 666 in 2546417.

Advancing to step 1:
The number 666 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 666

Going ahead to step 2:
The number 666 fits into 25 0 times, leaving a remainder of 25.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 25, we end up with 25.
Grab the next digit (4) from the dividend, add it to 25, then carry on: 254 / 666

Moving on to step 3:
254 divided by 666 is 0 with a remainder of 254.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 254 and we're left with 254.
Include the next digit (6) from the dividend after 254, then repeat: 2546 / 666

Going ahead to step 4:
666 goes into 2546 3 times with a remainder of 548.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 548 after subtracting 1998 from 2546.
Include the next digit (4) from the dividend after 548, then repeat: 5484 / 666

Step 5:
666 goes into 5484 8 times with a remainder of 156.
The next digit of our result is 8. 
Result so far: 38.0
Subtract 5328 from 5484 to get 156.
Append the next digit (1) from the dividend to 156 and continue with: 1561 / 666

Moving on to step 6:
The number 666 fits into 1561 2 times, leaving a remainder of 229.
The number 2 becomes the next digit in our result. 
Result so far: 382.0
Deduct 1332 from 1561 and we're left with 229.
Append the next digit (7) from the dividend to 229 and continue with: 2297 / 666

Going ahead to step 7:
666 goes into 2297 3 times with a remainder of 299.
Put 3 as the next digit of the answer. 
Result so far: 3823.0
The remainder is 299 after subtracting 1998 from 2297.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2990, and continue the process.

Step 8:
When dividing 2990 by 666, we get 4 with a remainder of 326.
The number 4 becomes the next digit in our result. 
Result so far: 3823.4
If we take 2664 away from 2990, we end up with 326.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3260, and continue the process.

Going ahead to step 9:
666 goes into 3260 4 times with a remainder of 596.
Record the quotient 4 as the next digit in the result. 
Result so far: 3823.44
If we subtract 2664 from 3260, we get 596.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5960, and continue the process.

The final result is 3823.44 with a remainder of 0.596.