Let's divide 873439 by 15
The aim is to understand the frequency of 15 in 873439.

Going ahead to step 1:
If we divide 8 by 15, we get 0 and a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 15

Advancing to step 2:
If we divide 87 by 15, we get 5 and a remainder of 12.
Use 5 as the next digit of our solution. 
Result so far: 5.0
If we take 75 away from 87, we end up with 12.
Include the next digit (3) from the dividend after 12, then repeat: 123 / 15

On to step 3:
If we divide 123 by 15, we get 8 and a remainder of 3.
The next digit of our result is 8. 
Result so far: 58.0
Subtracting 120 from 123 leaves us with 3.
Include the next digit (4) from the dividend after 3, then repeat: 34 / 15

Going ahead to step 4:
15 can be fit into 34 2 times, resulting in a remainder of 4.
Write down 2 as next digit of the result. 
Result so far: 582.0
If we subtract 30 from 34, we get 4.
Append the next digit (3) from the dividend to 4 and continue with: 43 / 15

Going ahead to step 5:
The number 15 fits into 43 2 times, leaving a remainder of 13.
The next digit of our result is 2. 
Result so far: 5822.0
If we take 30 away from 43, we end up with 13.
Include the next digit (9) from the dividend after 13, then repeat: 139 / 15

Going ahead to step 6:
The number 15 fits into 139 9 times, leaving a remainder of 4.
Write down 9 as next digit of the result. 
Result so far: 58229.0
Subtracting 135 from 139 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 7:
The number 15 fits into 40 2 times, leaving a remainder of 10.
The next digit of our result is 2. 
Result so far: 58229.2
Deduct 30 from 40 and we're left 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.

Going ahead to step 8:
100 divided by 15 is 6 with a remainder of 10.
The number 6 becomes the next digit in our result. 
Result so far: 58229.26
Subtracting 90 from 100 leaves us 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.

On to step 9:
100 divided by 15 is 6 with a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 58229.266
If we take 90 away from 100, 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.

The quotient of the division is 58229.266, and the remainder is 0.001.