39987 divided by 99 
The aim is to understand the frequency of 99 in 39987.

Let's proceed to step 1:
99 can be fit into 3 0 times, resulting in a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 99

Let's proceed to step 2:
When dividing 39 by 99, we get 0 with a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 39 and we're left with 39.
Append the next digit (9) from the dividend to 39 and continue with: 399 / 99

Advancing to step 3:
The number 99 fits into 399 4 times, leaving a remainder of 3.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
The remainder is 3 after subtracting 396 from 399.
Take the next digit (8) from the dividend and append it to 3, then repeat: 38 / 99

Let's proceed to step 4:
If we divide 38 by 99, we get 0 and a remainder of 38.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
Subtract 0 from 38 to get 38.
Fetch the next digit (7) from the dividend, attach it to 38 and continue: 387 / 99

Step 5:
387 divided by 99 is 3 with a remainder of 90.
Put 3 as the next digit of the answer. 
Result so far: 403.0
If we take 297 away from 387, we end up with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Advancing to step 6:
99 can be fit into 900 9 times, resulting in a remainder of 9.
Record the quotient 9 as the next digit in the result. 
Result so far: 403.9
Deduct 891 from 900 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 7:
90 divided by 99 is 0 with a remainder of 90.
Write down 0 as next digit of the result. 
Result so far: 403.9
If we take 0 away from 90, we end up with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Step 8:
900 divided by 99 is 9 with a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 403.909
If we subtract 891 from 900, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 9:
99 can be fit into 90 0 times, resulting in a remainder of 90.
The next digit of our result is 0. 
Result so far: 403.909
Subtracting 0 from 90 leaves us with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Going ahead to step 10:
When dividing 900 by 99, we get 9 with a remainder of 9.
Write down 9 as next digit of the result. 
Result so far: 403.90909
Deduct 891 from 900 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 11:
When dividing 90 by 99, we get 0 with a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 403.90909
Deduct 0 from 90 and we're left with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Going ahead to step 12:
When dividing 900 by 99, we get 9 with a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 403.9090909
Subtract 891 from 900 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 13:
99 can be fit into 90 0 times, resulting in a remainder of 90.
Write down 0 as next digit of the result. 
Result so far: 403.9090909
Subtract 0 from 90 to get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

In conclusion, the division gives 403.9090909 with a balance of 9e-08.