Let's divide 91251507 by 666
The aim is to understand the frequency of 666 in 91251507.

Moving on to step 1:
If we divide 9 by 666, we get 0 and a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Fetch the next digit (1) from the dividend, attach it to 9 and continue: 91 / 666

Moving on to step 2:
When dividing 91 by 666, we get 0 with a remainder of 91.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 91, we get 91.
Append the next digit (2) from the dividend to 91 and continue with: 912 / 666

Moving on to step 3:
912 divided by 666 is 1 with a remainder of 246.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 666 from 912 leaves us with 246.
Take the next digit (5) from the dividend and append it to 246, then repeat: 2465 / 666

Advancing to step 4:
The number 666 fits into 2465 3 times, leaving a remainder of 467.
The number 3 becomes the next digit in our result. 
Result so far: 13.0
If we take 1998 away from 2465, we end up with 467.
Grab the next digit (1) from the dividend, add it to 467, then carry on: 4671 / 666

Let's proceed to step 5:
4671 divided by 666 is 7 with a remainder of 9.
Write down 7 as next digit of the result. 
Result so far: 137.0
Deduct 4662 from 4671 and we're left with 9.
Bring next digit (5) of the dividend behind the 9 and repeat the process: 95 / 666

Step 6:
When dividing 95 by 666, we get 0 with a remainder of 95.
Write down 0 as next digit of the result. 
Result so far: 1370.0
Deduct 0 from 95 and we're left with 95.
Append the next digit (0) from the dividend to 95 and continue with: 950 / 666

Going ahead to step 7:
666 goes into 950 1 times with a remainder of 284.
Write down 1 as next digit of the result. 
Result so far: 13701.0
If we subtract 666 from 950, we get 284.
Grab the next digit (7) from the dividend, add it to 284, then carry on: 2847 / 666

Moving on to step 8:
When dividing 2847 by 666, we get 4 with a remainder of 183.
Put 4 as the next digit of the answer. 
Result so far: 137014.0
Subtract 2664 from 2847 to get 183.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1830, and continue the process.

Moving on to step 9:
1830 divided by 666 is 2 with a remainder of 498.
Put 2 as the next digit of the answer. 
Result so far: 137014.2
Deduct 1332 from 1830 and we're left with 498.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Advancing to step 10:
When dividing 4980 by 666, we get 7 with a remainder of 318.
The next digit of our result is 7. 
Result so far: 137014.27
If we subtract 4662 from 4980, we get 318.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3180, and continue the process.

On to step 11:
3180 divided by 666 is 4 with a remainder of 516.
The number 4 becomes the next digit in our result. 
Result so far: 137014.274
If we take 2664 away from 3180, we end up with 516.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5160, and continue the process.

Let's proceed to step 12:
The number 666 fits into 5160 7 times, leaving a remainder of 498.
Write down 7 as next digit of the result. 
Result so far: 137014.2747
The remainder is 498 after subtracting 4662 from 5160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Advancing to step 13:
666 goes into 4980 7 times with a remainder of 318.
Write down 7 as next digit of the result. 
Result so far: 137014.27477
Subtract 4662 from 4980 to get 318.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3180, and continue the process.

After the division, we end up with 137014.27477 and a remainder of 0.000318.