405645 divided by 78 
The aim is to understand the frequency of 78 in 405645.

Let's proceed to step 1:
The number 78 fits into 4 0 times, leaving a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Grab the next digit (0) from the dividend, add it to 4, then carry on: 40 / 78

Advancing to step 2:
The number 78 fits into 40 0 times, leaving a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 40 and we're left with 40.
Fetch the next digit (5) from the dividend, attach it to 40 and continue: 405 / 78

Let's proceed to step 3:
78 can be fit into 405 5 times, resulting in a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Subtracting 390 from 405 leaves us with 15.
Fetch the next digit (6) from the dividend, attach it to 15 and continue: 156 / 78

Let's proceed to step 4:
156 divided by 78 is 2 with a remainder of 0.
The next digit of our result is 2. 
Result so far: 52.0
If we subtract 156 from 156, we get 0.
Bring next digit (4) of the dividend behind the 0 and repeat the process: 4 / 78

On to step 5:
78 goes into 4 0 times with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 520.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (5) from the dividend and append it to 4, then repeat: 45 / 78

Advancing to step 6:
If we divide 45 by 78, we get 0 and a remainder of 45.
Put 0 as the next digit of the answer. 
Result so far: 5200.0
Subtracting 0 from 45 leaves us with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Let's proceed to step 7:
78 can be fit into 450 5 times, resulting in a remainder of 60.
The number 5 becomes the next digit in our result. 
Result so far: 5200.5
Subtracting 390 from 450 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Advancing to step 8:
When dividing 600 by 78, we get 7 with a remainder of 54.
The number 7 becomes the next digit in our result. 
Result so far: 5200.57
If we subtract 546 from 600, we get 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Advancing to step 9:
If we divide 540 by 78, we get 6 and a remainder of 72.
Record the quotient 6 as the next digit in the result. 
Result so far: 5200.576
The remainder is 72 after subtracting 468 from 540.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Step 10:
720 divided by 78 is 9 with a remainder of 18.
Record the quotient 9 as the next digit in the result. 
Result so far: 5200.5769
Subtracting 702 from 720 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 11:
180 divided by 78 is 2 with a remainder of 24.
Record the quotient 2 as the next digit in the result. 
Result so far: 5200.57692
Deduct 156 from 180 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 12:
78 can be fit into 240 3 times, resulting in a remainder of 6.
The next digit of our result is 3. 
Result so far: 5200.576923
The remainder is 6 after subtracting 234 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 13:
60 divided by 78 is 0 with a remainder of 60.
The next digit of our result is 0. 
Result so far: 5200.576923
If we take 0 away from 60, we end up with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Let's proceed to step 14:
78 goes into 600 7 times with a remainder of 54.
The next digit of our result is 7. 
Result so far: 5200.57692307
Deduct 546 from 600 and we're left with 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

The final outcome is 5200.57692307, with a leftover of 5.4e-08.