We divide 15969790 by 9
The aim is to understand the frequency of 9 in 15969790.

Advancing to step 1:
If we divide 1 by 9, we get 0 and a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Fetch the next digit (5) from the dividend, attach it to 1 and continue: 15 / 9

Moving on to step 2:
15 divided by 9 is 1 with a remainder of 6.
Write down 1 as next digit of the result. 
Result so far: 1.0
The remainder is 6 after subtracting 9 from 15.
Include the next digit (9) from the dividend after 6, then repeat: 69 / 9

Let's proceed to step 3:
9 goes into 69 7 times with a remainder of 6.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
The remainder is 6 after subtracting 63 from 69.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 9

Advancing to step 4:
9 goes into 66 7 times with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 177.0
The remainder is 3 after subtracting 63 from 66.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 9

Step 5:
When dividing 39 by 9, we get 4 with a remainder of 3.
Use 4 as the next digit of our solution. 
Result so far: 1774.0
If we take 36 away from 39, we end up with 3.
Fetch the next digit (7) from the dividend, attach it to 3 and continue: 37 / 9

Moving on to step 6:
9 goes into 37 4 times with a remainder of 1.
The next digit of our result is 4. 
Result so far: 17744.0
Deduct 36 from 37 and we're left with 1.
Take the next digit (9) from the dividend and append it to 1, then repeat: 19 / 9

Going ahead to step 7:
If we divide 19 by 9, we get 2 and a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 177442.0
If we subtract 18 from 19, we get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 9

Going ahead to step 8:
10 divided by 9 is 1 with a remainder of 1.
Write down 1 as next digit of the result. 
Result so far: 1774421.0
If we subtract 9 from 10, we get 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 9:
9 goes into 10 1 times with a remainder of 1.
Put 1 as the next digit of the answer. 
Result so far: 1774421.1
The remainder is 1 after subtracting 9 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 10:
9 can be fit into 10 1 times, resulting in a remainder of 1.
The next digit of our result is 1. 
Result so far: 1774421.11
If we take 9 away from 10, we end up 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.

After the division, we end up with 1774421.11 and a remainder of 0.001.