We look at the division of 639786 by 13 
The aim is to understand the frequency of 13 in 639786.

Moving on to step 1:
If we divide 6 by 13, we get 0 and a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 13

On to step 2:
When dividing 63 by 13, we get 4 with a remainder of 11.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Subtracting 52 from 63 leaves us with 11.
Append the next digit (9) from the dividend to 11 and continue with: 119 / 13

Step 3:
13 goes into 119 9 times with a remainder of 2.
The next digit of our result is 9. 
Result so far: 49.0
If we take 117 away from 119, we end up with 2.
Grab the next digit (7) from the dividend, add it to 2, then carry on: 27 / 13

Going ahead to step 4:
The number 13 fits into 27 2 times, leaving a remainder of 1.
Put 2 as the next digit of the answer. 
Result so far: 492.0
If we take 26 away from 27, we end up with 1.
Include the next digit (8) from the dividend after 1, then repeat: 18 / 13

On to step 5:
13 can be fit into 18 1 times, resulting in a remainder of 5.
Record the quotient 1 as the next digit in the result. 
Result so far: 4921.0
If we subtract 13 from 18, we get 5.
Grab the next digit (6) from the dividend, add it to 5, then carry on: 56 / 13

Let's proceed to step 6:
13 goes into 56 4 times with a remainder of 4.
Write down 4 as next digit of the result. 
Result so far: 49214.0
If we take 52 away from 56, we end up 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 7:
13 can be fit into 40 3 times, resulting in a remainder of 1.
Use 3 as the next digit of our solution. 
Result so far: 49214.3
If we subtract 39 from 40, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 8:
10 divided by 13 is 0 with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 49214.3
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 9:
The number 13 fits into 100 7 times, leaving a remainder of 9.
Use 7 as the next digit of our solution. 
Result so far: 49214.307
Deduct 91 from 100 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 10:
If we divide 90 by 13, we get 6 and a remainder of 12.
Use 6 as the next digit of our solution. 
Result so far: 49214.3076
The remainder is 12 after subtracting 78 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 11:
The number 13 fits into 120 9 times, leaving a remainder of 3.
Write down 9 as next digit of the result. 
Result so far: 49214.30769
Subtract 117 from 120 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 12:
The number 13 fits into 30 2 times, leaving a remainder of 4.
Put 2 as the next digit of the answer. 
Result so far: 49214.307692
Subtract 26 from 30 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.

Going ahead to step 13:
The number 13 fits into 40 3 times, leaving a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 49214.3076923
Subtracting 39 from 40 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 14:
The number 13 fits into 10 0 times, leaving a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 49214.3076923
If we take 0 away from 10, we end up 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.

The final result is 49214.3076923 with a remainder of 1e-08.