We look at the division of 421175 by 39 
The aim is to understand the frequency of 39 in 421175.

Advancing to step 1:
39 goes into 4 0 times with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 39

Advancing to step 2:
If we divide 42 by 39, we get 1 and a remainder of 3.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 3 after subtracting 39 from 42.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 39

Step 3:
If we divide 31 by 39, we get 0 and a remainder of 31.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Subtract 0 from 31 to get 31.
Include the next digit (1) from the dividend after 31, then repeat: 311 / 39

Going ahead to step 4:
If we divide 311 by 39, we get 7 and a remainder of 38.
Put 7 as the next digit of the answer. 
Result so far: 107.0
The remainder is 38 after subtracting 273 from 311.
Take the next digit (7) from the dividend and append it to 38, then repeat: 387 / 39

Step 5:
When dividing 387 by 39, we get 9 with a remainder of 36.
Put 9 as the next digit of the answer. 
Result so far: 1079.0
If we take 351 away from 387, we end up with 36.
Include the next digit (5) from the dividend after 36, then repeat: 365 / 39

Moving on to step 6:
If we divide 365 by 39, we get 9 and a remainder of 14.
The number 9 becomes the next digit in our result. 
Result so far: 10799.0
If we take 351 away from 365, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Let's proceed to step 7:
39 goes into 140 3 times with a remainder of 23.
Write down 3 as next digit of the result. 
Result so far: 10799.3
Subtract 117 from 140 to get 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Let's proceed to step 8:
39 can be fit into 230 5 times, resulting in a remainder of 35.
Write down 5 as next digit of the result. 
Result so far: 10799.35
Deduct 195 from 230 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Step 9:
If we divide 350 by 39, we get 8 and a remainder of 38.
Write down 8 as next digit of the result. 
Result so far: 10799.358
The remainder is 38 after subtracting 312 from 350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Going ahead to step 10:
380 divided by 39 is 9 with a remainder of 29.
Write down 9 as next digit of the result. 
Result so far: 10799.3589
Subtracting 351 from 380 leaves us with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

On to step 11:
39 goes into 290 7 times with a remainder of 17.
The next digit of our result is 7. 
Result so far: 10799.35897
Subtract 273 from 290 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 12:
39 goes into 170 4 times with a remainder of 14.
Record the quotient 4 as the next digit in the result. 
Result so far: 10799.358974
Subtracting 156 from 170 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 13:
140 divided by 39 is 3 with a remainder of 23.
Record the quotient 3 as the next digit in the result. 
Result so far: 10799.3589743
If we take 117 away from 140, we end up with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Advancing to step 14:
The number 39 fits into 230 5 times, leaving a remainder of 35.
The next digit of our result is 5. 
Result so far: 10799.35897435
If we subtract 195 from 230, we get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

The quotient of the division is 10799.35897435, and the remainder is 3.5e-08.