Let's divide 497924 by 21
The aim is to understand the frequency of 21 in 497924.

Advancing to step 1:
21 goes into 4 0 times with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Take the next digit (9) from the dividend and append it to 4, then repeat: 49 / 21

Let's proceed to step 2:
When dividing 49 by 21, we get 2 with a remainder of 7.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we take 42 away from 49, we end up with 7.
Bring next digit (7) of the dividend behind the 7 and repeat the process: 77 / 21

Advancing to step 3:
21 goes into 77 3 times with a remainder of 14.
The next digit of our result is 3. 
Result so far: 23.0
Deduct 63 from 77 and we're left with 14.
Append the next digit (9) from the dividend to 14 and continue with: 149 / 21

Step 4:
21 can be fit into 149 7 times, resulting in a remainder of 2.
Put 7 as the next digit of the answer. 
Result so far: 237.0
Subtract 147 from 149 to get 2.
Take the next digit (2) from the dividend and append it to 2, then repeat: 22 / 21

Moving on to step 5:
22 divided by 21 is 1 with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 2371.0
The remainder is 1 after subtracting 21 from 22.
Include the next digit (4) from the dividend after 1, then repeat: 14 / 21

On to step 6:
14 divided by 21 is 0 with a remainder of 14.
Record the quotient 0 as the next digit in the result. 
Result so far: 23710.0
The remainder is 14 after subtracting 0 from 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 7:
21 goes into 140 6 times with a remainder of 14.
Record the quotient 6 as the next digit in the result. 
Result so far: 23710.6
Deduct 126 from 140 and we're left with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 8:
21 goes into 140 6 times with a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 23710.66
Subtracting 126 from 140 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

The final outcome is 23710.66, with a leftover of 0.014.