993636 ÷ 21 
The aim is to understand the frequency of 21 in 993636.

Going ahead to step 1:
21 can be fit into 9 0 times, resulting in a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 21

On to step 2:
The number 21 fits into 99 4 times, leaving a remainder of 15.
The next digit of our result is 4. 
Result so far: 4.0
If we subtract 84 from 99, we get 15.
Take the next digit (3) from the dividend and append it to 15, then repeat: 153 / 21

Advancing to step 3:
21 goes into 153 7 times with a remainder of 6.
The number 7 becomes the next digit in our result. 
Result so far: 47.0
The remainder is 6 after subtracting 147 from 153.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 21

Let's proceed to step 4:
The number 21 fits into 66 3 times, leaving a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 473.0
Subtract 63 from 66 to get 3.
Append the next digit (3) from the dividend to 3 and continue with: 33 / 21

On to step 5:
21 can be fit into 33 1 times, resulting in a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 4731.0
The remainder is 12 after subtracting 21 from 33.
Bring next digit (6) of the dividend behind the 12 and repeat the process: 126 / 21

On to step 6:
If we divide 126 by 21, we get 6 and a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 47316.0
If we take 126 away from 126, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 7:
0 divided by 21 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 47316.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 8:
21 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 47316.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

In conclusion, the division gives 47316.0 with a balance of 0.0.