We look at the division of 3986063 by 345 
The aim is to understand the frequency of 345 in 3986063.

Advancing to step 1:
When dividing 3 by 345, we get 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 345

Advancing to step 2:
The number 345 fits into 39 0 times, leaving a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 39, we end up with 39.
Bring next digit (8) of the dividend behind the 39 and repeat the process: 398 / 345

Going ahead to step 3:
If we divide 398 by 345, we get 1 and a remainder of 53.
The next digit of our result is 1. 
Result so far: 1.0
If we take 345 away from 398, we end up with 53.
Bring next digit (6) of the dividend behind the 53 and repeat the process: 536 / 345

Let's proceed to step 4:
345 goes into 536 1 times with a remainder of 191.
Write down 1 as next digit of the result. 
Result so far: 11.0
Subtract 345 from 536 to get 191.
Append the next digit (0) from the dividend to 191 and continue with: 1910 / 345

Let's proceed to step 5:
When dividing 1910 by 345, we get 5 with a remainder of 185.
The next digit of our result is 5. 
Result so far: 115.0
Subtracting 1725 from 1910 leaves us with 185.
Fetch the next digit (6) from the dividend, attach it to 185 and continue: 1856 / 345

Let's proceed to step 6:
When dividing 1856 by 345, we get 5 with a remainder of 131.
The number 5 becomes the next digit in our result. 
Result so far: 1155.0
If we take 1725 away from 1856, we end up with 131.
Append the next digit (3) from the dividend to 131 and continue with: 1313 / 345

Moving on to step 7:
The number 345 fits into 1313 3 times, leaving a remainder of 278.
Use 3 as the next digit of our solution. 
Result so far: 11553.0
Subtracting 1035 from 1313 leaves us with 278.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2780, and continue the process.

Step 8:
The number 345 fits into 2780 8 times, leaving a remainder of 20.
The number 8 becomes the next digit in our result. 
Result so far: 11553.8
Deduct 2760 from 2780 and we're left 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.

Let's proceed to step 9:
The number 345 fits into 200 0 times, leaving a remainder of 200.
The next digit of our result is 0. 
Result so far: 11553.8
If we subtract 0 from 200, we get 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

On to step 10:
2000 divided by 345 is 5 with a remainder of 275.
The number 5 becomes the next digit in our result. 
Result so far: 11553.805
The remainder is 275 after subtracting 1725 from 2000.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2750, and continue the process.

Step 11:
When dividing 2750 by 345, we get 7 with a remainder of 335.
Put 7 as the next digit of the answer. 
Result so far: 11553.8057
Subtracting 2415 from 2750 leaves us with 335.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3350, and continue the process.

Let's proceed to step 12:
345 can be fit into 3350 9 times, resulting in a remainder of 245.
Write down 9 as next digit of the result. 
Result so far: 11553.80579
The remainder is 245 after subtracting 3105 from 3350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2450, and continue the process.

Moving on to step 13:
2450 divided by 345 is 7 with a remainder of 35.
The next digit of our result is 7. 
Result so far: 11553.805797
The remainder is 35 after subtracting 2415 from 2450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Advancing to step 14:
The number 345 fits into 350 1 times, leaving a remainder of 5.
Use 1 as the next digit of our solution. 
Result so far: 11553.8057971
If we take 345 away from 350, 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.

Moving on to step 15:
The number 345 fits into 50 0 times, leaving a remainder of 50.
The next digit of our result is 0. 
Result so far: 11553.8057971
If we take 0 away from 50, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

The final outcome is 11553.8057971, with a leftover of 5e-08.