We're dividing 646810 by 9 
The aim is to understand the frequency of 9 in 646810.

Moving on to step 1:
When dividing 6 by 9, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 9

Moving on to step 2:
If we divide 64 by 9, we get 7 and a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
If we take 63 away from 64, we end up with 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 9

On to step 3:
9 can be fit into 16 1 times, resulting in a remainder of 7.
The next digit of our result is 1. 
Result so far: 71.0
Deduct 9 from 16 and we're left with 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 9

On to step 4:
9 can be fit into 78 8 times, resulting in a remainder of 6.
The number 8 becomes the next digit in our result. 
Result so far: 718.0
Subtract 72 from 78 to get 6.
Grab the next digit (1) from the dividend, add it to 6, then carry on: 61 / 9

Let's proceed to step 5:
The number 9 fits into 61 6 times, leaving a remainder of 7.
Write down 6 as next digit of the result. 
Result so far: 7186.0
If we take 54 away from 61, we end up with 7.
Take the next digit (0) from the dividend and append it to 7, then repeat: 70 / 9

Going ahead to step 6:
If we divide 70 by 9, we get 7 and a remainder of 7.
Record the quotient 7 as the next digit in the result. 
Result so far: 71867.0
If we subtract 63 from 70, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Step 7:
9 can be fit into 70 7 times, resulting in a remainder of 7.
The number 7 becomes the next digit in our result. 
Result so far: 71867.7
Deduct 63 from 70 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 8:
9 can be fit into 70 7 times, resulting in a remainder of 7.
The next digit of our result is 7. 
Result so far: 71867.77
If we take 63 away from 70, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The quotient of the division is 71867.77, and the remainder is 0.007.