We look at the division of 780346 by 15 
The aim is to understand the frequency of 15 in 780346.

Moving on to step 1:
15 goes into 7 0 times with a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 15

Advancing to step 2:
When dividing 78 by 15, we get 5 with a remainder of 3.
The next digit of our result is 5. 
Result so far: 5.0
The remainder is 3 after subtracting 75 from 78.
Take the next digit (0) from the dividend and append it to 3, then repeat: 30 / 15

On to step 3:
When dividing 30 by 15, we get 2 with a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 52.0
Subtracting 30 from 30 leaves us with 0.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 15

Moving on to step 4:
15 goes into 3 0 times with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 520.0
Deduct 0 from 3 and we're left with 3.
Fetch the next digit (4) from the dividend, attach it to 3 and continue: 34 / 15

Advancing to step 5:
The number 15 fits into 34 2 times, leaving a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 5202.0
If we take 30 away from 34, we end up with 4.
Fetch the next digit (6) from the dividend, attach it to 4 and continue: 46 / 15

Going ahead to step 6:
When dividing 46 by 15, we get 3 with a remainder of 1.
The next digit of our result is 3. 
Result so far: 52023.0
Deduct 45 from 46 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 7:
10 divided by 15 is 0 with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 52023.0
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
The number 15 fits into 100 6 times, leaving a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 52023.06
Subtract 90 from 100 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 9:
When dividing 100 by 15, we get 6 with a remainder of 10.
Use 6 as the next digit of our solution. 
Result so far: 52023.066
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Our division results in 52023.066 with a remaining 0.001.