We look at the division of 812878 by 12 
The aim is to understand the frequency of 12 in 812878.

Going ahead to step 1:
12 goes into 8 0 times with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Take the next digit (1) from the dividend and append it to 8, then repeat: 81 / 12

Going ahead to step 2:
The number 12 fits into 81 6 times, leaving a remainder of 9.
The next digit of our result is 6. 
Result so far: 6.0
Subtracting 72 from 81 leaves us with 9.
Append the next digit (2) from the dividend to 9 and continue with: 92 / 12

Going ahead to step 3:
92 divided by 12 is 7 with a remainder of 8.
Write down 7 as next digit of the result. 
Result so far: 67.0
Subtracting 84 from 92 leaves us with 8.
Include the next digit (8) from the dividend after 8, then repeat: 88 / 12

Let's proceed to step 4:
12 goes into 88 7 times with a remainder of 4.
The number 7 becomes the next digit in our result. 
Result so far: 677.0
Subtracting 84 from 88 leaves us with 4.
Take the next digit (7) from the dividend and append it to 4, then repeat: 47 / 12

Moving on to step 5:
47 divided by 12 is 3 with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 6773.0
If we subtract 36 from 47, we get 11.
Take the next digit (8) from the dividend and append it to 11, then repeat: 118 / 12

On to step 6:
118 divided by 12 is 9 with a remainder of 10.
Use 9 as the next digit of our solution. 
Result so far: 67739.0
Deduct 108 from 118 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 7:
When dividing 100 by 12, we get 8 with a remainder of 4.
Put 8 as the next digit of the answer. 
Result so far: 67739.8
Subtracting 96 from 100 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.

Step 8:
The number 12 fits into 40 3 times, leaving a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 67739.83
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.

Moving on to step 9:
12 goes into 40 3 times with a remainder of 4.
Put 3 as the next digit of the answer. 
Result so far: 67739.833
Subtract 36 from 40 to 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.

The final outcome is 67739.833, with a leftover of 0.0004.