We look at the division of 31237 by 39 
The aim is to understand the frequency of 39 in 31237.

On to step 1:
39 goes into 3 0 times with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Append the next digit (1) from the dividend to 3 and continue with: 31 / 39

Moving on to step 2:
31 divided by 39 is 0 with a remainder of 31.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 31, we end up with 31.
Fetch the next digit (2) from the dividend, attach it to 31 and continue: 312 / 39

Advancing to step 3:
If we divide 312 by 39, we get 8 and a remainder of 0.
Record the quotient 8 as the next digit in the result. 
Result so far: 8.0
Subtracting 312 from 312 leaves us with 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 39

On to step 4:
When dividing 3 by 39, we get 0 with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 80.0
Deduct 0 from 3 and we're left with 3.
Include the next digit (7) from the dividend after 3, then repeat: 37 / 39

On to step 5:
If we divide 37 by 39, we get 0 and a remainder of 37.
Use 0 as the next digit of our solution. 
Result so far: 800.0
Subtract 0 from 37 to get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Advancing to step 6:
39 goes into 370 9 times with a remainder of 19.
The next digit of our result is 9. 
Result so far: 800.9
Deduct 351 from 370 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 7:
When dividing 190 by 39, we get 4 with a remainder of 34.
The number 4 becomes the next digit in our result. 
Result so far: 800.94
If we take 156 away from 190, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Step 8:
If we divide 340 by 39, we get 8 and a remainder of 28.
Put 8 as the next digit of the answer. 
Result so far: 800.948
Subtract 312 from 340 to get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Advancing to step 9:
If we divide 280 by 39, we get 7 and a remainder of 7.
The number 7 becomes the next digit in our result. 
Result so far: 800.9487
Subtracting 273 from 280 leaves us 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.

Going ahead to step 10:
When dividing 70 by 39, we get 1 with a remainder of 31.
Record the quotient 1 as the next digit in the result. 
Result so far: 800.94871
If we subtract 39 from 70, we get 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Advancing to step 11:
When dividing 310 by 39, we get 7 with a remainder of 37.
Record the quotient 7 as the next digit in the result. 
Result so far: 800.948717
If we take 273 away from 310, we end up with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

On to step 12:
When dividing 370 by 39, we get 9 with a remainder of 19.
The number 9 becomes the next digit in our result. 
Result so far: 800.9487179
Subtracting 351 from 370 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 13:
39 goes into 190 4 times with a remainder of 34.
Record the quotient 4 as the next digit in the result. 
Result so far: 800.94871794
Subtracting 156 from 190 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

The quotient of the division is 800.94871794, and the remainder is 3.4e-08.