We divide 399350 by 12
The aim is to understand the frequency of 12 in 399350.

Let's proceed to step 1:
When dividing 3 by 12, we get 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 12

On to step 2:
If we divide 39 by 12, we get 3 and a remainder of 3.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
The remainder is 3 after subtracting 36 from 39.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 12

Going ahead to step 3:
If we divide 39 by 12, we get 3 and a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 33.0
Deduct 36 from 39 and we're left with 3.
Take the next digit (3) from the dividend and append it to 3, then repeat: 33 / 12

Going ahead to step 4:
The number 12 fits into 33 2 times, leaving a remainder of 9.
Write down 2 as next digit of the result. 
Result so far: 332.0
If we subtract 24 from 33, we get 9.
Bring next digit (5) of the dividend behind the 9 and repeat the process: 95 / 12

Moving on to step 5:
The number 12 fits into 95 7 times, leaving a remainder of 11.
The number 7 becomes the next digit in our result. 
Result so far: 3327.0
Subtract 84 from 95 to get 11.
Include the next digit (0) from the dividend after 11, then repeat: 110 / 12

Step 6:
The number 12 fits into 110 9 times, leaving a remainder of 2.
Put 9 as the next digit of the answer. 
Result so far: 33279.0
Subtracting 108 from 110 leaves us 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.

On to step 7:
12 can be fit into 20 1 times, resulting in a remainder of 8.
Put 1 as the next digit of the answer. 
Result so far: 33279.1
If we take 12 away from 20, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 8:
If we divide 80 by 12, we get 6 and a remainder of 8.
The number 6 becomes the next digit in our result. 
Result so far: 33279.16
Subtract 72 from 80 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 9:
When dividing 80 by 12, we get 6 with a remainder of 8.
Use 6 as the next digit of our solution. 
Result so far: 33279.166
The remainder is 8 after subtracting 72 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

After the division, we end up with 33279.166 and a remainder of 0.0008.