We're dividing 6688491 by 7 
The aim is to understand the frequency of 7 in 6688491.

Step 1:
The number 7 fits into 6 0 times, leaving a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 7

On to step 2:
66 divided by 7 is 9 with a remainder of 3.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
If we subtract 63 from 66, we get 3.
Take the next digit (8) from the dividend and append it to 3, then repeat: 38 / 7

Step 3:
38 divided by 7 is 5 with a remainder of 3.
Use 5 as the next digit of our solution. 
Result so far: 95.0
Deduct 35 from 38 and we're left with 3.
Bring next digit (8) of the dividend behind the 3 and repeat the process: 38 / 7

Let's proceed to step 4:
7 can be fit into 38 5 times, resulting in a remainder of 3.
The number 5 becomes the next digit in our result. 
Result so far: 955.0
The remainder is 3 after subtracting 35 from 38.
Take the next digit (4) from the dividend and append it to 3, then repeat: 34 / 7

Moving on to step 5:
7 goes into 34 4 times with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 9554.0
Subtract 28 from 34 to get 6.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 7

Step 6:
When dividing 69 by 7, we get 9 with a remainder of 6.
Use 9 as the next digit of our solution. 
Result so far: 95549.0
If we take 63 away from 69, we end up with 6.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 7

Step 7:
7 can be fit into 61 8 times, resulting in a remainder of 5.
The next digit of our result is 8. 
Result so far: 955498.0
Subtracting 56 from 61 leaves us 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 8:
If we divide 50 by 7, we get 7 and a remainder of 1.
Use 7 as the next digit of our solution. 
Result so far: 955498.7
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.

Going ahead to step 9:
If we divide 10 by 7, we get 1 and a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 955498.71
The remainder is 3 after subtracting 7 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 10:
When dividing 30 by 7, we get 4 with a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 955498.714
The remainder is 2 after subtracting 28 from 30.
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 11:
7 goes into 20 2 times with a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 955498.7142
If we take 14 away from 20, we end up 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.

Let's proceed to step 12:
7 can be fit into 60 8 times, resulting in a remainder of 4.
The next digit of our result is 8. 
Result so far: 955498.71428
If we take 56 away from 60, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 13:
The number 7 fits into 40 5 times, leaving a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 955498.714285
Subtract 35 from 40 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.

Let's proceed to step 14:
7 goes into 50 7 times with a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 955498.7142857
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.

On to step 15:
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: 955498.71428571
Subtracting 7 from 10 leaves us 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.

In conclusion, the division gives 955498.71428571 with a balance of 3e-09.