We look at the division of 502409 by 39 
The aim is to understand the frequency of 39 in 502409.

Advancing to step 1:
39 goes into 5 0 times with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (0) from the dividend to 5 and continue with: 50 / 39

On to step 2:
If we divide 50 by 39, we get 1 and a remainder of 11.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we take 39 away from 50, we end up with 11.
Take the next digit (2) from the dividend and append it to 11, then repeat: 112 / 39

Step 3:
When dividing 112 by 39, we get 2 with a remainder of 34.
Write down 2 as next digit of the result. 
Result so far: 12.0
Subtracting 78 from 112 leaves us with 34.
Bring next digit (4) of the dividend behind the 34 and repeat the process: 344 / 39

Going ahead to step 4:
When dividing 344 by 39, we get 8 with a remainder of 32.
Record the quotient 8 as the next digit in the result. 
Result so far: 128.0
Deduct 312 from 344 and we're left with 32.
Take the next digit (0) from the dividend and append it to 32, then repeat: 320 / 39

Advancing to step 5:
If we divide 320 by 39, we get 8 and a remainder of 8.
The next digit of our result is 8. 
Result so far: 1288.0
The remainder is 8 after subtracting 312 from 320.
Grab the next digit (9) from the dividend, add it to 8, then carry on: 89 / 39

Let's proceed to step 6:
39 can be fit into 89 2 times, resulting in a remainder of 11.
The number 2 becomes the next digit in our result. 
Result so far: 12882.0
The remainder is 11 after subtracting 78 from 89.
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 7:
If we divide 110 by 39, we get 2 and a remainder of 32.
Record the quotient 2 as the next digit in the result. 
Result so far: 12882.2
If we subtract 78 from 110, we get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

On to step 8:
39 goes into 320 8 times with a remainder of 8.
Write down 8 as next digit of the result. 
Result so far: 12882.28
Subtract 312 from 320 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.

Moving on to step 9:
39 can be fit into 80 2 times, resulting in a remainder of 2.
Record the quotient 2 as the next digit in the result. 
Result so far: 12882.282
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.

Advancing to step 10:
39 goes into 20 0 times with a remainder of 20.
The next digit of our result is 0. 
Result so far: 12882.282
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 11:
39 goes into 200 5 times with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 12882.28205
If we take 195 away from 200, we end up 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.

Step 12:
39 can be fit into 50 1 times, resulting in a remainder of 11.
The number 1 becomes the next digit in our result. 
Result so far: 12882.282051
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.

Step 13:
39 can be fit into 110 2 times, resulting in a remainder of 32.
Put 2 as the next digit of the answer. 
Result so far: 12882.2820512
The remainder is 32 after subtracting 78 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Step 14:
If we divide 320 by 39, we get 8 and a remainder of 8.
Record the quotient 8 as the next digit in the result. 
Result so far: 12882.28205128
If we subtract 312 from 320, we 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.

After the division, we end up with 12882.28205128 and a remainder of 8e-09.