399117 ÷ 9 
The aim is to understand the frequency of 9 in 399117.

Advancing to step 1:
9 can be fit into 3 0 times, resulting in a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 9

Advancing to step 2:
If we divide 39 by 9, we get 4 and a remainder of 3.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtract 36 from 39 to get 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 9

Advancing to step 3:
If we divide 39 by 9, we get 4 and a remainder of 3.
Record the quotient 4 as the next digit in the result. 
Result so far: 44.0
Subtracting 36 from 39 leaves us with 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 9

Moving on to step 4:
9 goes into 31 3 times with a remainder of 4.
Write down 3 as next digit of the result. 
Result so far: 443.0
Subtract 27 from 31 to get 4.
Include the next digit (1) from the dividend after 4, then repeat: 41 / 9

Moving on to step 5:
9 goes into 41 4 times with a remainder of 5.
Put 4 as the next digit of the answer. 
Result so far: 4434.0
Deduct 36 from 41 and we're left with 5.
Append the next digit (7) from the dividend to 5 and continue with: 57 / 9

Going ahead to step 6:
9 can be fit into 57 6 times, resulting in a remainder of 3.
Use 6 as the next digit of our solution. 
Result so far: 44346.0
Subtracting 54 from 57 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.

Advancing to step 7:
When dividing 30 by 9, we get 3 with a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 44346.3
If we take 27 away from 30, 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.

Going ahead to step 8:
When dividing 30 by 9, we get 3 with a remainder of 3.
Use 3 as the next digit of our solution. 
Result so far: 44346.33
If we take 27 away from 30, 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.

The quotient of the division is 44346.33, and the remainder is 0.003.