We look at the division of 303390 by 39 
The aim is to understand the frequency of 39 in 303390.

Let's proceed to step 1:
3 divided by 39 is 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Fetch the next digit (0) from the dividend, attach it to 3 and continue: 30 / 39

Step 2:
30 divided by 39 is 0 with a remainder of 30.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 30 leaves us with 30.
Append the next digit (3) from the dividend to 30 and continue with: 303 / 39

Let's proceed to step 3:
39 can be fit into 303 7 times, resulting in a remainder of 30.
The next digit of our result is 7. 
Result so far: 7.0
The remainder is 30 after subtracting 273 from 303.
Take the next digit (3) from the dividend and append it to 30, then repeat: 303 / 39

Going ahead to step 4:
303 divided by 39 is 7 with a remainder of 30.
Use 7 as the next digit of our solution. 
Result so far: 77.0
Deduct 273 from 303 and we're left with 30.
Bring next digit (9) of the dividend behind the 30 and repeat the process: 309 / 39

Step 5:
39 can be fit into 309 7 times, resulting in a remainder of 36.
The number 7 becomes the next digit in our result. 
Result so far: 777.0
The remainder is 36 after subtracting 273 from 309.
Include the next digit (0) from the dividend after 36, then repeat: 360 / 39

Let's proceed to step 6:
If we divide 360 by 39, we get 9 and a remainder of 9.
The next digit of our result is 9. 
Result so far: 7779.0
The remainder is 9 after subtracting 351 from 360.
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 7:
39 can be fit into 90 2 times, resulting in a remainder of 12.
Put 2 as the next digit of the answer. 
Result so far: 7779.2
If we take 78 away from 90, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 8:
If we divide 120 by 39, we get 3 and a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 7779.23
Deduct 117 from 120 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 9:
When dividing 30 by 39, we get 0 with a remainder of 30.
The next digit of our result is 0. 
Result so far: 7779.23
Deduct 0 from 30 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 10:
When dividing 300 by 39, we get 7 with a remainder of 27.
Write down 7 as next digit of the result. 
Result so far: 7779.2307
If we take 273 away from 300, we end up with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Let's proceed to step 11:
If we divide 270 by 39, we get 6 and a remainder of 36.
The next digit of our result is 6. 
Result so far: 7779.23076
Subtracting 234 from 270 leaves us with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Going ahead to step 12:
39 can be fit into 360 9 times, resulting in a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 7779.230769
If we subtract 351 from 360, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 13:
When dividing 90 by 39, we get 2 with a remainder of 12.
The number 2 becomes the next digit in our result. 
Result so far: 7779.2307692
If we take 78 away from 90, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 14:
120 divided by 39 is 3 with a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 7779.23076923
Subtracting 117 from 120 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

In conclusion, the division gives 7779.23076923 with a balance of 3e-09.