We look at the division of 730441 by 21 
The aim is to understand the frequency of 21 in 730441.

Step 1:
21 goes into 7 0 times with a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Bring next digit (3) of the dividend behind the 7 and repeat the process: 73 / 21

Let's proceed to step 2:
21 goes into 73 3 times with a remainder of 10.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we subtract 63 from 73, we get 10.
Append the next digit (0) from the dividend to 10 and continue with: 100 / 21

Moving on to step 3:
21 goes into 100 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 34.0
The remainder is 16 after subtracting 84 from 100.
Append the next digit (4) from the dividend to 16 and continue with: 164 / 21

On to step 4:
When dividing 164 by 21, we get 7 with a remainder of 17.
The next digit of our result is 7. 
Result so far: 347.0
Deduct 147 from 164 and we're left with 17.
Grab the next digit (4) from the dividend, add it to 17, then carry on: 174 / 21

Step 5:
When dividing 174 by 21, we get 8 with a remainder of 6.
Write down 8 as next digit of the result. 
Result so far: 3478.0
Subtracting 168 from 174 leaves us with 6.
Take the next digit (1) from the dividend and append it to 6, then repeat: 61 / 21

Going ahead to step 6:
21 goes into 61 2 times with a remainder of 19.
Use 2 as the next digit of our solution. 
Result so far: 34782.0
The remainder is 19 after subtracting 42 from 61.
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 7:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 34782.9
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.

On to step 8:
21 goes into 10 0 times with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 34782.9
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.

Going ahead to step 9:
21 goes into 100 4 times with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 34782.904
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.

On to step 10:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 34782.9047
Deduct 147 from 160 and we're left 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.

Let's proceed to step 11:
130 divided by 21 is 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 34782.90476
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 12:
40 divided by 21 is 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 34782.904761
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.

Going ahead to step 13:
21 goes into 190 9 times with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 34782.9047619
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.

On to step 14:
When dividing 10 by 21, we get 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 34782.9047619
If we subtract 0 from 10, we 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.

The final result is 34782.9047619 with a remainder of 1e-08.