637988 ÷ 9 
The aim is to understand the frequency of 9 in 637988.

Let's proceed to step 1:
When dividing 6 by 9, we get 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 9

Let's proceed to step 2:
63 divided by 9 is 7 with a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 7.0
The remainder is 0 after subtracting 63 from 63.
Bring next digit (7) of the dividend behind the 0 and repeat the process: 7 / 9

On to step 3:
7 divided by 9 is 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 70.0
Deduct 0 from 7 and we're left with 7.
Fetch the next digit (9) from the dividend, attach it to 7 and continue: 79 / 9

Advancing to step 4:
79 divided by 9 is 8 with a remainder of 7.
The next digit of our result is 8. 
Result so far: 708.0
The remainder is 7 after subtracting 72 from 79.
Take the next digit (8) from the dividend and append it to 7, then repeat: 78 / 9

Going ahead to step 5:
78 divided by 9 is 8 with a remainder of 6.
The number 8 becomes the next digit in our result. 
Result so far: 7088.0
The remainder is 6 after subtracting 72 from 78.
Fetch the next digit (8) from the dividend, attach it to 6 and continue: 68 / 9

On to step 6:
9 goes into 68 7 times with a remainder of 5.
Use 7 as the next digit of our solution. 
Result so far: 70887.0
Deduct 63 from 68 and we're left 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.

Advancing to step 7:
When dividing 50 by 9, we get 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 70887.5
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.

Let's proceed to step 8:
50 divided by 9 is 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 70887.55
The remainder is 5 after subtracting 45 from 50.
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 70887.55, and the remainder is 0.005.