We look at the division of 454705 by 21 
The aim is to understand the frequency of 21 in 454705.

Step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 21

Going ahead to step 2:
When dividing 45 by 21, we get 2 with a remainder of 3.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we subtract 42 from 45, we get 3.
Grab the next digit (4) from the dividend, add it to 3, then carry on: 34 / 21

Let's proceed to step 3:
When dividing 34 by 21, we get 1 with a remainder of 13.
Put 1 as the next digit of the answer. 
Result so far: 21.0
Subtract 21 from 34 to get 13.
Fetch the next digit (7) from the dividend, attach it to 13 and continue: 137 / 21

Moving on to step 4:
When dividing 137 by 21, we get 6 with a remainder of 11.
Write down 6 as next digit of the result. 
Result so far: 216.0
The remainder is 11 after subtracting 126 from 137.
Take the next digit (0) from the dividend and append it to 11, then repeat: 110 / 21

Moving on to step 5:
110 divided by 21 is 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 2165.0
The remainder is 5 after subtracting 105 from 110.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 21

Let's proceed to step 6:
21 can be fit into 55 2 times, resulting in a remainder of 13.
The next digit of our result is 2. 
Result so far: 21652.0
Subtracting 42 from 55 leaves us 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 7:
130 divided by 21 is 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 21652.6
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.

On to step 8:
40 divided by 21 is 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 21652.61
If we subtract 21 from 40, we get 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 9:
190 divided by 21 is 9 with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 21652.619
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.

Going ahead to step 10:
21 goes into 10 0 times with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 21652.619
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.

On to step 11:
If we divide 100 by 21, we get 4 and a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 21652.61904
If we take 84 away from 100, we end up 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.

Let's proceed to step 12:
21 can be fit into 160 7 times, resulting in a remainder of 13.
The next digit of our result is 7. 
Result so far: 21652.619047
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.

Going ahead to step 13:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 21652.6190476
Subtracting 126 from 130 leaves us 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.

On to step 14:
21 goes into 40 1 times with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 21652.61904761
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Our division results in 21652.61904761 with a remaining 1.9e-08.