We look at the division of 329052 by 21 
The aim is to understand the frequency of 21 in 329052.

On to step 1:
21 can be fit into 3 0 times, resulting in a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Grab the next digit (2) from the dividend, add it to 3, then carry on: 32 / 21

Let's proceed to step 2:
If we divide 32 by 21, we get 1 and a remainder of 11.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 21 from 32, we get 11.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 21

Step 3:
If we divide 119 by 21, we get 5 and a remainder of 14.
Put 5 as the next digit of the answer. 
Result so far: 15.0
Subtract 105 from 119 to get 14.
Take the next digit (0) from the dividend and append it to 14, then repeat: 140 / 21

On to step 4:
If we divide 140 by 21, we get 6 and a remainder of 14.
The number 6 becomes the next digit in our result. 
Result so far: 156.0
If we take 126 away from 140, we end up with 14.
Bring next digit (5) of the dividend behind the 14 and repeat the process: 145 / 21

Moving on to step 5:
21 goes into 145 6 times with a remainder of 19.
The number 6 becomes the next digit in our result. 
Result so far: 1566.0
If we take 126 away from 145, we end up with 19.
Grab the next digit (2) from the dividend, add it to 19, then carry on: 192 / 21

Going ahead to step 6:
If we divide 192 by 21, we get 9 and a remainder of 3.
The next digit of our result is 9. 
Result so far: 15669.0
If we subtract 189 from 192, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 7:
30 divided by 21 is 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 15669.1
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 8:
21 goes into 90 4 times with a remainder of 6.
The next digit of our result is 4. 
Result so far: 15669.14
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 9:
60 divided by 21 is 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 15669.142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 10:
If we divide 180 by 21, we get 8 and a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 15669.1428
If we subtract 168 from 180, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 11:
When dividing 120 by 21, we get 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 15669.14285
Subtract 105 from 120 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 12:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 15669.142857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 13:
If we divide 30 by 21, we get 1 and a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 15669.1428571
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 14:
21 can be fit into 90 4 times, resulting in a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 15669.14285714
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

In conclusion, the division gives 15669.14285714 with a balance of 6e-09.