638702 ÷ 15 
The aim is to understand the frequency of 15 in 638702.

Going ahead to step 1:
6 divided by 15 is 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 15

Let's proceed to step 2:
63 divided by 15 is 4 with a remainder of 3.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtract 60 from 63 to get 3.
Fetch the next digit (8) from the dividend, attach it to 3 and continue: 38 / 15

Step 3:
When dividing 38 by 15, we get 2 with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 42.0
If we subtract 30 from 38, we get 8.
Append the next digit (7) from the dividend to 8 and continue with: 87 / 15

Going ahead to step 4:
If we divide 87 by 15, we get 5 and a remainder of 12.
The number 5 becomes the next digit in our result. 
Result so far: 425.0
If we take 75 away from 87, we end up with 12.
Include the next digit (0) from the dividend after 12, then repeat: 120 / 15

Moving on to step 5:
15 can be fit into 120 8 times, resulting in a remainder of 0.
The next digit of our result is 8. 
Result so far: 4258.0
Subtracting 120 from 120 leaves us with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 15

Step 6:
The number 15 fits into 2 0 times, leaving a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 42580.0
Deduct 0 from 2 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 7:
15 goes into 20 1 times with a remainder of 5.
Use 1 as the next digit of our solution. 
Result so far: 42580.1
Subtracting 15 from 20 leaves us 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:
If we divide 50 by 15, we get 3 and a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 42580.13
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.

Let's proceed to step 9:
If we divide 50 by 15, we get 3 and a remainder of 5.
Use 3 as the next digit of our solution. 
Result so far: 42580.133
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.

After the division, we end up with 42580.133 and a remainder of 0.0005.