71209 divided by 13 
The aim is to understand the frequency of 13 in 71209.

Step 1:
When dividing 7 by 13, we get 0 with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Grab the next digit (1) from the dividend, add it to 7, then carry on: 71 / 13

Advancing to step 2:
If we divide 71 by 13, we get 5 and a remainder of 6.
Use 5 as the next digit of our solution. 
Result so far: 5.0
Subtracting 65 from 71 leaves us with 6.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 13

Going ahead to step 3:
If we divide 62 by 13, we get 4 and a remainder of 10.
Write down 4 as next digit of the result. 
Result so far: 54.0
Deduct 52 from 62 and we're left with 10.
Include the next digit (0) from the dividend after 10, then repeat: 100 / 13

Going ahead to step 4:
100 divided by 13 is 7 with a remainder of 9.
Put 7 as the next digit of the answer. 
Result so far: 547.0
The remainder is 9 after subtracting 91 from 100.
Bring next digit (9) of the dividend behind the 9 and repeat the process: 99 / 13

Step 5:
99 divided by 13 is 7 with a remainder of 8.
The next digit of our result is 7. 
Result so far: 5477.0
If we take 91 away from 99, 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 6:
The number 13 fits into 80 6 times, leaving a remainder of 2.
Put 6 as the next digit of the answer. 
Result so far: 5477.6
If we subtract 78 from 80, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 7:
13 can be fit into 20 1 times, resulting in a remainder of 7.
Put 1 as the next digit of the answer. 
Result so far: 5477.61
If we take 13 away from 20, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 8:
70 divided by 13 is 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 5477.615
Deduct 65 from 70 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 9:
13 can be fit into 50 3 times, resulting in a remainder of 11.
Use 3 as the next digit of our solution. 
Result so far: 5477.6153
The remainder is 11 after subtracting 39 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 10:
The number 13 fits into 110 8 times, leaving a remainder of 6.
Put 8 as the next digit of the answer. 
Result so far: 5477.61538
Subtracting 104 from 110 leaves us 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.

Step 11:
When dividing 60 by 13, we get 4 with a remainder of 8.
Use 4 as the next digit of our solution. 
Result so far: 5477.615384
Subtract 52 from 60 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.

Going ahead to step 12:
When dividing 80 by 13, we get 6 with a remainder of 2.
Put 6 as the next digit of the answer. 
Result so far: 5477.6153846
If we subtract 78 from 80, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 13:
If we divide 20 by 13, we get 1 and a remainder of 7.
Record the quotient 1 as the next digit in the result. 
Result so far: 5477.61538461
Deduct 13 from 20 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The quotient of the division is 5477.61538461, and the remainder is 7e-09.