666258 ÷ 7 
The aim is to understand the frequency of 7 in 666258.

Let's proceed to step 1:
7 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 7

On to step 2:
If we divide 66 by 7, we get 9 and a remainder of 3.
Use 9 as the next digit of our solution. 
Result so far: 9.0
Subtract 63 from 66 to get 3.
Take the next digit (6) from the dividend and append it to 3, then repeat: 36 / 7

Let's proceed to step 3:
The number 7 fits into 36 5 times, leaving a remainder of 1.
Put 5 as the next digit of the answer. 
Result so far: 95.0
Deduct 35 from 36 and we're left with 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 7

Going ahead to step 4:
The number 7 fits into 12 1 times, leaving a remainder of 5.
Record the quotient 1 as the next digit in the result. 
Result so far: 951.0
If we subtract 7 from 12, we get 5.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 7

Step 5:
The number 7 fits into 55 7 times, leaving a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 9517.0
If we take 49 away from 55, we end up with 6.
Include the next digit (8) from the dividend after 6, then repeat: 68 / 7

Going ahead to step 6:
7 goes into 68 9 times with a remainder of 5.
Record the quotient 9 as the next digit in the result. 
Result so far: 95179.0
Subtract 63 from 68 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 7:
When dividing 50 by 7, we get 7 with a remainder of 1.
Write down 7 as next digit of the result. 
Result so far: 95179.7
If we subtract 49 from 50, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 8:
10 divided by 7 is 1 with a remainder of 3.
Put 1 as the next digit of the answer. 
Result so far: 95179.71
If we take 7 away from 10, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 9:
30 divided by 7 is 4 with a remainder of 2.
The number 4 becomes the next digit in our result. 
Result so far: 95179.714
Subtracting 28 from 30 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 10:
20 divided by 7 is 2 with a remainder of 6.
Put 2 as the next digit of the answer. 
Result so far: 95179.7142
Deduct 14 from 20 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 11:
7 can be fit into 60 8 times, resulting in a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 95179.71428
If we subtract 56 from 60, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 12:
If we divide 40 by 7, we get 5 and a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 95179.714285
Deduct 35 from 40 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 13:
7 goes into 50 7 times with a remainder of 1.
The next digit of our result is 7. 
Result so far: 95179.7142857
The remainder is 1 after subtracting 49 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 14:
When dividing 10 by 7, we get 1 with a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 95179.71428571
Deduct 7 from 10 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

The final result is 95179.71428571 with a remainder of 3e-09.