We look at the division of 39861568 by 12 
The aim is to understand the frequency of 12 in 39861568.

Step 1:
12 goes into 3 0 times with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 12

Going ahead to step 2:
12 goes into 39 3 times with a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 36 from 39, we get 3.
Append the next digit (8) from the dividend to 3 and continue with: 38 / 12

Moving on to step 3:
12 goes into 38 3 times with a remainder of 2.
Record the quotient 3 as the next digit in the result. 
Result so far: 33.0
If we subtract 36 from 38, we get 2.
Append the next digit (6) from the dividend to 2 and continue with: 26 / 12

Step 4:
26 divided by 12 is 2 with a remainder of 2.
The number 2 becomes the next digit in our result. 
Result so far: 332.0
If we subtract 24 from 26, we get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 12

Advancing to step 5:
The number 12 fits into 21 1 times, leaving a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 3321.0
Subtract 12 from 21 to get 9.
Append the next digit (5) from the dividend to 9 and continue with: 95 / 12

Let's proceed to step 6:
12 can be fit into 95 7 times, resulting in a remainder of 11.
The next digit of our result is 7. 
Result so far: 33217.0
Subtracting 84 from 95 leaves us with 11.
Bring next digit (6) of the dividend behind the 11 and repeat the process: 116 / 12

On to step 7:
If we divide 116 by 12, we get 9 and a remainder of 8.
Put 9 as the next digit of the answer. 
Result so far: 332179.0
The remainder is 8 after subtracting 108 from 116.
Bring next digit (8) of the dividend behind the 8 and repeat the process: 88 / 12

Going ahead to step 8:
12 goes into 88 7 times with a remainder of 4.
The number 7 becomes the next digit in our result. 
Result so far: 3321797.0
If we subtract 84 from 88, 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.

On to step 9:
12 can be fit into 40 3 times, resulting in a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 3321797.3
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.

On to step 10:
40 divided by 12 is 3 with a remainder of 4.
The number 3 becomes the next digit in our result. 
Result so far: 3321797.33
Subtracting 36 from 40 leaves us 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.

After the division, we end up with 3321797.33 and a remainder of 0.004.