We're dividing 393940 by 12 
The aim is to understand the frequency of 12 in 393940.

Advancing to step 1:
If we divide 3 by 12, we get 0 and 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.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 12

On to step 2:
When dividing 39 by 12, we get 3 with a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 3.0
The remainder is 3 after subtracting 36 from 39.
Include the next digit (3) from the dividend after 3, then repeat: 33 / 12

Moving on to step 3:
When dividing 33 by 12, we get 2 with a remainder of 9.
Write down 2 as next digit of the result. 
Result so far: 32.0
If we subtract 24 from 33, we get 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 12

Going ahead to step 4:
12 goes into 99 8 times with a remainder of 3.
Put 8 as the next digit of the answer. 
Result so far: 328.0
If we take 96 away from 99, we end up with 3.
Fetch the next digit (4) from the dividend, attach it to 3 and continue: 34 / 12

Let's proceed to step 5:
If we divide 34 by 12, we get 2 and a remainder of 10.
The next digit of our result is 2. 
Result so far: 3282.0
The remainder is 10 after subtracting 24 from 34.
Include the next digit (0) from the dividend after 10, then repeat: 100 / 12

Step 6:
100 divided by 12 is 8 with a remainder of 4.
The next digit of our result is 8. 
Result so far: 32828.0
If we subtract 96 from 100, 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.

Step 7:
12 can be fit into 40 3 times, resulting in a remainder of 4.
Write down 3 as next digit of the result. 
Result so far: 32828.3
Deduct 36 from 40 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.

Step 8:
The number 12 fits into 40 3 times, leaving a remainder of 4.
The next digit of our result is 3. 
Result so far: 32828.33
The remainder is 4 after subtracting 36 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The quotient of the division is 32828.33, and the remainder is 0.004.