We look at the division of 492265 by 21 
The aim is to understand the frequency of 21 in 492265.

Let's proceed to step 1:
The number 21 fits into 4 0 times, leaving a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (9) from the dividend and append it to 4, then repeat: 49 / 21

Going ahead to step 2:
If we divide 49 by 21, we get 2 and a remainder of 7.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 42 from 49 and we're left with 7.
Fetch the next digit (2) from the dividend, attach it to 7 and continue: 72 / 21

Step 3:
If we divide 72 by 21, we get 3 and a remainder of 9.
Use 3 as the next digit of our solution. 
Result so far: 23.0
Subtracting 63 from 72 leaves us with 9.
Fetch the next digit (2) from the dividend, attach it to 9 and continue: 92 / 21

Step 4:
The number 21 fits into 92 4 times, leaving a remainder of 8.
Use 4 as the next digit of our solution. 
Result so far: 234.0
Deduct 84 from 92 and we're left with 8.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 21

Moving on to step 5:
21 can be fit into 86 4 times, resulting in a remainder of 2.
The next digit of our result is 4. 
Result so far: 2344.0
Subtract 84 from 86 to get 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 21

Advancing to step 6:
The number 21 fits into 25 1 times, leaving a remainder of 4.
Record the quotient 1 as the next digit in the result. 
Result so far: 23441.0
If we subtract 21 from 25, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 7:
21 goes into 40 1 times with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 23441.1
If we take 21 away from 40, we end up with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 8:
When dividing 190 by 21, we get 9 with a remainder of 1.
The next digit of our result is 9. 
Result so far: 23441.19
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 9:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The next digit of our result is 0. 
Result so far: 23441.19
Subtracting 0 from 10 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 10:
21 goes into 100 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 23441.1904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 11:
When dividing 160 by 21, we get 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 23441.19047
Subtract 147 from 160 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

On to step 12:
If we divide 130 by 21, we get 6 and a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 23441.190476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 13:
If we divide 40 by 21, we get 1 and a remainder of 19.
The next digit of our result is 1. 
Result so far: 23441.1904761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 14:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 23441.19047619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

After the division, we end up with 23441.19047619 and a remainder of 1e-09.