We're dividing 459449 by 21 
The aim is to understand the frequency of 21 in 459449.

Moving on to step 1:
If we divide 4 by 21, we get 0 and 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.
Grab the next digit (5) from the dividend, add it to 4, then carry on: 45 / 21

Going ahead to step 2:
When dividing 45 by 21, we get 2 with a remainder of 3.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 42 from 45, we get 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 21

Moving on to step 3:
The number 21 fits into 39 1 times, leaving a remainder of 18.
Record the quotient 1 as the next digit in the result. 
Result so far: 21.0
If we subtract 21 from 39, we get 18.
Append the next digit (4) from the dividend to 18 and continue with: 184 / 21

Step 4:
When dividing 184 by 21, we get 8 with a remainder of 16.
The next digit of our result is 8. 
Result so far: 218.0
If we take 168 away from 184, we end up with 16.
Include the next digit (4) from the dividend after 16, then repeat: 164 / 21

On to step 5:
21 goes into 164 7 times with a remainder of 17.
Write down 7 as next digit of the result. 
Result so far: 2187.0
Subtract 147 from 164 to get 17.
Fetch the next digit (9) from the dividend, attach it to 17 and continue: 179 / 21

Step 6:
21 goes into 179 8 times with a remainder of 11.
Write down 8 as next digit of the result. 
Result so far: 21878.0
If we subtract 168 from 179, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 7:
If we divide 110 by 21, we get 5 and a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 21878.5
Subtracting 105 from 110 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 8:
50 divided by 21 is 2 with a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 21878.52
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 9:
If we divide 80 by 21, we get 3 and a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 21878.523
Deduct 63 from 80 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 10:
If we divide 170 by 21, we get 8 and a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 21878.5238
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 11:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 21878.5238
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 12:
If we divide 200 by 21, we get 9 and a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 21878.523809
If we take 189 away from 200, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 13:
If we divide 110 by 21, we get 5 and a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 21878.5238095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 14:
If we divide 50 by 21, we get 2 and a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 21878.52380952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 21878.52380952 with a remaining 8e-09.