We look at the division of 78439588 by 78 
The aim is to understand the frequency of 78 in 78439588.

Going ahead to step 1:
78 can be fit into 7 0 times, resulting in a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 78

Let's proceed to step 2:
78 goes into 78 1 times with a remainder of 0.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 78 from 78 to get 0.
Grab the next digit (4) from the dividend, add it to 0, then carry on: 4 / 78

Advancing to step 3:
The number 78 fits into 4 0 times, leaving a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 10.0
Subtracting 0 from 4 leaves us with 4.
Fetch the next digit (3) from the dividend, attach it to 4 and continue: 43 / 78

Moving on to step 4:
When dividing 43 by 78, we get 0 with a remainder of 43.
The number 0 becomes the next digit in our result. 
Result so far: 100.0
If we subtract 0 from 43, we get 43.
Append the next digit (9) from the dividend to 43 and continue with: 439 / 78

Let's proceed to step 5:
When dividing 439 by 78, we get 5 with a remainder of 49.
Use 5 as the next digit of our solution. 
Result so far: 1005.0
The remainder is 49 after subtracting 390 from 439.
Append the next digit (5) from the dividend to 49 and continue with: 495 / 78

Step 6:
78 goes into 495 6 times with a remainder of 27.
Write down 6 as next digit of the result. 
Result so far: 10056.0
If we subtract 468 from 495, we get 27.
Include the next digit (8) from the dividend after 27, then repeat: 278 / 78

Moving on to step 7:
The number 78 fits into 278 3 times, leaving a remainder of 44.
Put 3 as the next digit of the answer. 
Result so far: 100563.0
If we subtract 234 from 278, we get 44.
Include the next digit (8) from the dividend after 44, then repeat: 448 / 78

Going ahead to step 8:
448 divided by 78 is 5 with a remainder of 58.
Put 5 as the next digit of the answer. 
Result so far: 1005635.0
Deduct 390 from 448 and we're left with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Step 9:
78 can be fit into 580 7 times, resulting in a remainder of 34.
Record the quotient 7 as the next digit in the result. 
Result so far: 1005635.7
Deduct 546 from 580 and we're left with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

On to step 10:
340 divided by 78 is 4 with a remainder of 28.
Put 4 as the next digit of the answer. 
Result so far: 1005635.74
Subtract 312 from 340 to get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

On to step 11:
280 divided by 78 is 3 with a remainder of 46.
Use 3 as the next digit of our solution. 
Result so far: 1005635.743
If we subtract 234 from 280, we get 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Step 12:
78 goes into 460 5 times with a remainder of 70.
Use 5 as the next digit of our solution. 
Result so far: 1005635.7435
Subtracting 390 from 460 leaves us with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Going ahead to step 13:
The number 78 fits into 700 8 times, leaving a remainder of 76.
Use 8 as the next digit of our solution. 
Result so far: 1005635.74358
If we take 624 away from 700, we end up with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Moving on to step 14:
If we divide 760 by 78, we get 9 and a remainder of 58.
Put 9 as the next digit of the answer. 
Result so far: 1005635.743589
If we take 702 away from 760, we end up with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 15:
When dividing 580 by 78, we get 7 with a remainder of 34.
Put 7 as the next digit of the answer. 
Result so far: 1005635.7435897
If we take 546 away from 580, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Step 16:
When dividing 340 by 78, we get 4 with a remainder of 28.
Use 4 as the next digit of our solution. 
Result so far: 1005635.74358974
Subtract 312 from 340 to get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

The final outcome is 1005635.74358974, with a leftover of 2.8e-08.