We look at the division of 881290 by 13 
The aim is to understand the frequency of 13 in 881290.

Advancing to step 1:
The number 13 fits into 8 0 times, leaving a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (8) of the dividend behind the 8 and repeat the process: 88 / 13

Advancing to step 2:
13 goes into 88 6 times with a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 6.0
Subtracting 78 from 88 leaves us with 10.
Bring next digit (1) of the dividend behind the 10 and repeat the process: 101 / 13

Moving on to step 3:
When dividing 101 by 13, we get 7 with a remainder of 10.
Use 7 as the next digit of our solution. 
Result so far: 67.0
If we take 91 away from 101, we end up with 10.
Take the next digit (2) from the dividend and append it to 10, then repeat: 102 / 13

Let's proceed to step 4:
The number 13 fits into 102 7 times, leaving a remainder of 11.
Record the quotient 7 as the next digit in the result. 
Result so far: 677.0
Deduct 91 from 102 and we're left with 11.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 13

Moving on to step 5:
When dividing 119 by 13, we get 9 with a remainder of 2.
Use 9 as the next digit of our solution. 
Result so far: 6779.0
Subtract 117 from 119 to get 2.
Append the next digit (0) from the dividend to 2 and continue with: 20 / 13

On to step 6:
13 can be fit into 20 1 times, resulting in a remainder of 7.
The number 1 becomes the next digit in our result. 
Result so far: 67791.0
The remainder is 7 after subtracting 13 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 7:
13 goes into 70 5 times with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 67791.5
The remainder is 5 after subtracting 65 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 8:
When dividing 50 by 13, we get 3 with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 67791.53
If we take 39 away from 50, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 9:
110 divided by 13 is 8 with a remainder of 6.
The number 8 becomes the next digit in our result. 
Result so far: 67791.538
If we take 104 away from 110, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 10:
If we divide 60 by 13, we get 4 and a remainder of 8.
Write down 4 as next digit of the result. 
Result so far: 67791.5384
Subtracting 52 from 60 leaves us 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.

Moving on to step 11:
80 divided by 13 is 6 with a remainder of 2.
Write down 6 as next digit of the result. 
Result so far: 67791.53846
The remainder is 2 after subtracting 78 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 12:
The number 13 fits into 20 1 times, leaving a remainder of 7.
The next digit of our result is 1. 
Result so far: 67791.538461
The remainder is 7 after subtracting 13 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 13:
If we divide 70 by 13, we get 5 and a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 67791.5384615
Subtract 65 from 70 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 14:
50 divided by 13 is 3 with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 67791.53846153
Subtracting 39 from 50 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

The final result is 67791.53846153 with a remainder of 1.1e-08.