Let's divide 824543 by 21
The aim is to understand the frequency of 21 in 824543.

Moving on to step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Include the next digit (2) from the dividend after 8, then repeat: 82 / 21

Moving on to step 2:
82 divided by 21 is 3 with a remainder of 19.
Use 3 as the next digit of our solution. 
Result so far: 3.0
If we subtract 63 from 82, we get 19.
Bring next digit (4) of the dividend behind the 19 and repeat the process: 194 / 21

Step 3:
21 can be fit into 194 9 times, resulting in a remainder of 5.
The next digit of our result is 9. 
Result so far: 39.0
If we take 189 away from 194, we end up with 5.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 21

Let's proceed to step 4:
If we divide 55 by 21, we get 2 and a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 392.0
If we subtract 42 from 55, we get 13.
Take the next digit (4) from the dividend and append it to 13, then repeat: 134 / 21

Advancing to step 5:
If we divide 134 by 21, we get 6 and a remainder of 8.
Record the quotient 6 as the next digit in the result. 
Result so far: 3926.0
Subtract 126 from 134 to get 8.
Include the next digit (3) from the dividend after 8, then repeat: 83 / 21

Step 6:
If we divide 83 by 21, we get 3 and a remainder of 20.
Use 3 as the next digit of our solution. 
Result so far: 39263.0
If we subtract 63 from 83, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 7:
When dividing 200 by 21, we get 9 with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 39263.9
If we subtract 189 from 200, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 8:
110 divided by 21 is 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 39263.95
The remainder is 5 after subtracting 105 from 110.
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:
The number 21 fits into 50 2 times, leaving a remainder of 8.
The next digit of our result is 2. 
Result so far: 39263.952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 10:
80 divided by 21 is 3 with a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 39263.9523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 11:
21 goes into 170 8 times with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 39263.95238
Deduct 168 from 170 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.

On to step 12:
20 divided by 21 is 0 with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 39263.95238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 13:
21 goes into 200 9 times with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 39263.9523809
Deduct 189 from 200 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 14:
When dividing 110 by 21, we get 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 39263.95238095
If we take 105 away from 110, 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.

The final outcome is 39263.95238095, with a leftover of 5e-09.