We're dividing 398201 by 78 
The aim is to understand the frequency of 78 in 398201.

Advancing to step 1:
When dividing 3 by 78, 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.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 78

Let's proceed to step 2:
78 can be fit into 39 0 times, resulting in a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 39 to get 39.
Grab the next digit (8) from the dividend, add it to 39, then carry on: 398 / 78

Moving on to step 3:
78 goes into 398 5 times with a remainder of 8.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
Subtract 390 from 398 to get 8.
Take the next digit (2) from the dividend and append it to 8, then repeat: 82 / 78

Let's proceed to step 4:
The number 78 fits into 82 1 times, leaving a remainder of 4.
The number 1 becomes the next digit in our result. 
Result so far: 51.0
If we take 78 away from 82, we end up with 4.
Fetch the next digit (0) from the dividend, attach it to 4 and continue: 40 / 78

Going ahead to step 5:
78 can be fit into 40 0 times, resulting in a remainder of 40.
Put 0 as the next digit of the answer. 
Result so far: 510.0
If we take 0 away from 40, we end up with 40.
Append the next digit (1) from the dividend to 40 and continue with: 401 / 78

Advancing to step 6:
401 divided by 78 is 5 with a remainder of 11.
Use 5 as the next digit of our solution. 
Result so far: 5105.0
If we subtract 390 from 401, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 7:
110 divided by 78 is 1 with a remainder of 32.
Record the quotient 1 as the next digit in the result. 
Result so far: 5105.1
If we take 78 away from 110, we end up with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Step 8:
320 divided by 78 is 4 with a remainder of 8.
Put 4 as the next digit of the answer. 
Result so far: 5105.14
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.

On to step 9:
If we divide 80 by 78, we get 1 and a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 5105.141
Subtract 78 from 80 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 10:
If we divide 20 by 78, we get 0 and a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 5105.141
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.

Moving on to step 11:
78 goes into 200 2 times with a remainder of 44.
Put 2 as the next digit of the answer. 
Result so far: 5105.14102
The remainder is 44 after subtracting 156 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Moving on to step 12:
When dividing 440 by 78, we get 5 with a remainder of 50.
The number 5 becomes the next digit in our result. 
Result so far: 5105.141025
If we take 390 away from 440, 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.

On to step 13:
500 divided by 78 is 6 with a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 5105.1410256
Subtract 468 from 500 to 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.

Let's proceed to step 14:
78 can be fit into 320 4 times, resulting in a remainder of 8.
The next digit of our result is 4. 
Result so far: 5105.14102564
Deduct 312 from 320 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 5105.14102564 with a remaining 8e-09.