We divide 477928 by 21
The aim is to understand the frequency of 21 in 477928.

Let's proceed to step 1:
If we divide 4 by 21, we get 0 and a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Bring next digit (7) of the dividend behind the 4 and repeat the process: 47 / 21

On to step 2:
21 goes into 47 2 times with a remainder of 5.
The next digit of our result is 2. 
Result so far: 2.0
If we take 42 away from 47, we end up with 5.
Fetch the next digit (7) from the dividend, attach it to 5 and continue: 57 / 21

On to step 3:
If we divide 57 by 21, we get 2 and a remainder of 15.
Put 2 as the next digit of the answer. 
Result so far: 22.0
Deduct 42 from 57 and we're left with 15.
Fetch the next digit (9) from the dividend, attach it to 15 and continue: 159 / 21

On to step 4:
21 can be fit into 159 7 times, resulting in a remainder of 12.
Write down 7 as next digit of the result. 
Result so far: 227.0
Subtract 147 from 159 to get 12.
Take the next digit (2) from the dividend and append it to 12, then repeat: 122 / 21

Moving on to step 5:
21 goes into 122 5 times with a remainder of 17.
The next digit of our result is 5. 
Result so far: 2275.0
Deduct 105 from 122 and we're left with 17.
Append the next digit (8) from the dividend to 17 and continue with: 178 / 21

Going ahead to step 6:
The number 21 fits into 178 8 times, leaving a remainder of 10.
Put 8 as the next digit of the answer. 
Result so far: 22758.0
The remainder is 10 after subtracting 168 from 178.
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 7:
21 can be fit into 100 4 times, resulting in a remainder of 16.
The next digit of our result is 4. 
Result so far: 22758.4
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.

Step 8:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 22758.47
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.

Let's proceed to step 9:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 22758.476
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.

Let's proceed to step 10:
When dividing 40 by 21, we get 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 22758.4761
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.

Let's proceed to step 11:
21 goes into 190 9 times with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 22758.47619
Subtracting 189 from 190 leaves us with 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 12:
If we divide 10 by 21, we get 0 and a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 22758.47619
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.

On to step 13:
21 goes into 100 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 22758.4761904
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 14:
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: 22758.47619047
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 22758.47619047 with a remainder of 1.3e-08.