Let's divide 91869641 by 78
The aim is to understand the frequency of 78 in 91869641.

On to step 1:
78 can be fit into 9 0 times, resulting in a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 9 after subtracting 0 from 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 78

Step 2:
When dividing 91 by 78, we get 1 with a remainder of 13.
The next digit of our result is 1. 
Result so far: 1.0
If we take 78 away from 91, we end up with 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 78

Advancing to step 3:
If we divide 138 by 78, we get 1 and a remainder of 60.
The next digit of our result is 1. 
Result so far: 11.0
Subtracting 78 from 138 leaves us with 60.
Include the next digit (6) from the dividend after 60, then repeat: 606 / 78

Let's proceed to step 4:
606 divided by 78 is 7 with a remainder of 60.
Record the quotient 7 as the next digit in the result. 
Result so far: 117.0
The remainder is 60 after subtracting 546 from 606.
Bring next digit (9) of the dividend behind the 60 and repeat the process: 609 / 78

Step 5:
78 can be fit into 609 7 times, resulting in a remainder of 63.
Put 7 as the next digit of the answer. 
Result so far: 1177.0
Subtract 546 from 609 to get 63.
Append the next digit (6) from the dividend to 63 and continue with: 636 / 78

Advancing to step 6:
If we divide 636 by 78, we get 8 and a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 11778.0
If we take 624 away from 636, we end up with 12.
Grab the next digit (4) from the dividend, add it to 12, then carry on: 124 / 78

Step 7:
78 goes into 124 1 times with a remainder of 46.
Record the quotient 1 as the next digit in the result. 
Result so far: 117781.0
Subtract 78 from 124 to get 46.
Fetch the next digit (1) from the dividend, attach it to 46 and continue: 461 / 78

Going ahead to step 8:
The number 78 fits into 461 5 times, leaving a remainder of 71.
The next digit of our result is 5. 
Result so far: 1177815.0
If we subtract 390 from 461, we get 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

On to step 9:
710 divided by 78 is 9 with a remainder of 8.
Use 9 as the next digit of our solution. 
Result so far: 1177815.9
Subtracting 702 from 710 leaves us 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.

Step 10:
The number 78 fits into 80 1 times, leaving a remainder of 2.
The next digit of our result is 1. 
Result so far: 1177815.91
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 11:
The number 78 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 1177815.91
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 12:
When dividing 200 by 78, we get 2 with a remainder of 44.
Write down 2 as next digit of the result. 
Result so far: 1177815.9102
Subtracting 156 from 200 leaves us with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Advancing to step 13:
When dividing 440 by 78, we get 5 with a remainder of 50.
Put 5 as the next digit of the answer. 
Result so far: 1177815.91025
If we subtract 390 from 440, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Advancing to step 14:
78 goes into 500 6 times with a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 1177815.910256
If we subtract 468 from 500, we 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.

Moving on to step 15:
78 goes into 320 4 times with a remainder of 8.
Write down 4 as next digit of the result. 
Result so far: 1177815.9102564
Subtracting 312 from 320 leaves us 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.

Step 16:
When dividing 80 by 78, we get 1 with a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1177815.91025641
If we take 78 away from 80, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final outcome is 1177815.91025641, with a leftover of 2e-09.