778331 divided by 15 
The aim is to understand the frequency of 15 in 778331.

Advancing to step 1:
When dividing 7 by 15, we get 0 with a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Take the next digit (7) from the dividend and append it to 7, then repeat: 77 / 15

Going ahead to step 2:
When dividing 77 by 15, we get 5 with a remainder of 2.
Use 5 as the next digit of our solution. 
Result so far: 5.0
If we subtract 75 from 77, we get 2.
Include the next digit (8) from the dividend after 2, then repeat: 28 / 15

Step 3:
The number 15 fits into 28 1 times, leaving a remainder of 13.
Use 1 as the next digit of our solution. 
Result so far: 51.0
Deduct 15 from 28 and we're left with 13.
Append the next digit (3) from the dividend to 13 and continue with: 133 / 15

Moving on to step 4:
The number 15 fits into 133 8 times, leaving a remainder of 13.
Write down 8 as next digit of the result. 
Result so far: 518.0
If we subtract 120 from 133, we get 13.
Bring next digit (3) of the dividend behind the 13 and repeat the process: 133 / 15

Moving on to step 5:
15 goes into 133 8 times with a remainder of 13.
The number 8 becomes the next digit in our result. 
Result so far: 5188.0
The remainder is 13 after subtracting 120 from 133.
Fetch the next digit (1) from the dividend, attach it to 13 and continue: 131 / 15

On to step 6:
131 divided by 15 is 8 with a remainder of 11.
The number 8 becomes the next digit in our result. 
Result so far: 51888.0
If we subtract 120 from 131, 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.

Going ahead to step 7:
15 can be fit into 110 7 times, resulting in a remainder of 5.
Record the quotient 7 as the next digit in the result. 
Result so far: 51888.7
If we take 105 away from 110, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 8:
15 can be fit into 50 3 times, resulting in a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 51888.73
If we take 45 away from 50, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 9:
When dividing 50 by 15, we get 3 with a remainder of 5.
Record the quotient 3 as the next digit in the result. 
Result so far: 51888.733
If we subtract 45 from 50, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

The quotient of the division is 51888.733, and the remainder is 0.0005.