We look at the division of 483241 by 21 
The aim is to understand the frequency of 21 in 483241.

Step 1:
4 divided by 21 is 0 with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Bring next digit (8) of the dividend behind the 4 and repeat the process: 48 / 21

Let's proceed to step 2:
48 divided by 21 is 2 with a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 42 from 48, we get 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 21

Let's proceed to step 3:
The number 21 fits into 63 3 times, leaving a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 23.0
If we take 63 away from 63, we end up with 0.
Grab the next digit (2) from the dividend, add it to 0, then carry on: 2 / 21

Let's proceed to step 4:
2 divided by 21 is 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 230.0
Deduct 0 from 2 and we're left with 2.
Append the next digit (4) from the dividend to 2 and continue with: 24 / 21

Moving on to step 5:
When dividing 24 by 21, we get 1 with a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 2301.0
If we take 21 away from 24, we end up with 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 21

Moving on to step 6:
If we divide 31 by 21, we get 1 and a remainder of 10.
Use 1 as the next digit of our solution. 
Result so far: 23011.0
Subtract 21 from 31 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 7:
If we divide 100 by 21, we get 4 and a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 23011.4
Deduct 84 from 100 and we're left 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 8:
When dividing 160 by 21, we get 7 with a remainder of 13.
The next digit of our result is 7. 
Result so far: 23011.47
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 9:
130 divided by 21 is 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 23011.476
Deduct 126 from 130 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 10:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 23011.4761
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.

Going ahead to step 11:
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: 23011.47619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 12:
10 divided by 21 is 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 23011.47619
If we take 0 away from 10, we end up 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 13:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 23011.4761904
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.

Step 14:
21 goes into 160 7 times with a remainder of 13.
The next digit of our result is 7. 
Result so far: 23011.47619047
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.

The final result is 23011.47619047 with a remainder of 1.3e-08.