642800 ÷ 7 
The aim is to understand the frequency of 7 in 642800.

Going ahead to step 1:
6 divided by 7 is 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 7

Step 2:
The number 7 fits into 64 9 times, leaving a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
Deduct 63 from 64 and we're left with 1.
Take the next digit (2) from the dividend and append it to 1, then repeat: 12 / 7

Let's proceed to step 3:
The number 7 fits into 12 1 times, leaving a remainder of 5.
The next digit of our result is 1. 
Result so far: 91.0
If we subtract 7 from 12, we get 5.
Grab the next digit (8) from the dividend, add it to 5, then carry on: 58 / 7

Step 4:
The number 7 fits into 58 8 times, leaving a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 918.0
If we subtract 56 from 58, we get 2.
Grab the next digit (0) from the dividend, add it to 2, then carry on: 20 / 7

Advancing to step 5:
If we divide 20 by 7, we get 2 and a remainder of 6.
The number 2 becomes the next digit in our result. 
Result so far: 9182.0
Subtracting 14 from 20 leaves us with 6.
Append the next digit (0) from the dividend to 6 and continue with: 60 / 7

Going ahead to step 6:
60 divided by 7 is 8 with a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 91828.0
Deduct 56 from 60 and we're left 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.

On to step 7:
When dividing 40 by 7, we get 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 91828.5
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.

Advancing to step 8:
When dividing 50 by 7, we get 7 with a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 91828.57
Subtracting 49 from 50 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 9:
7 goes into 10 1 times with a remainder of 3.
Write down 1 as next digit of the result. 
Result so far: 91828.571
Subtract 7 from 10 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 10:
7 goes into 30 4 times with a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 91828.5714
Deduct 28 from 30 and we're left 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.

Moving on to step 11:
7 can be fit into 20 2 times, resulting in a remainder of 6.
Write down 2 as next digit of the result. 
Result so far: 91828.57142
Subtracting 14 from 20 leaves us 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 12:
If we divide 60 by 7, we get 8 and a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 91828.571428
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:
When dividing 40 by 7, we get 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 91828.5714285
If we subtract 35 from 40, we 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.

Step 14:
7 can be fit into 50 7 times, resulting in a remainder of 1.
Write down 7 as next digit of the result. 
Result so far: 91828.57142857
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.

After the division, we end up with 91828.57142857 and a remainder of 1e-09.