We're dividing 475050 by 21 
The aim is to understand the frequency of 21 in 475050.

Going ahead to step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Grab the next digit (7) from the dividend, add it to 4, then carry on: 47 / 21

Moving on to step 2:
21 can be fit into 47 2 times, resulting in a remainder of 5.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtracting 42 from 47 leaves us with 5.
Grab the next digit (5) from the dividend, add it to 5, then carry on: 55 / 21

Going ahead to step 3:
55 divided by 21 is 2 with a remainder of 13.
Put 2 as the next digit of the answer. 
Result so far: 22.0
Subtracting 42 from 55 leaves us with 13.
Grab the next digit (0) from the dividend, add it to 13, then carry on: 130 / 21

Advancing to step 4:
If we divide 130 by 21, we get 6 and a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 226.0
The remainder is 4 after subtracting 126 from 130.
Append the next digit (5) from the dividend to 4 and continue with: 45 / 21

Let's proceed to step 5:
If we divide 45 by 21, we get 2 and a remainder of 3.
Write down 2 as next digit of the result. 
Result so far: 2262.0
Subtracting 42 from 45 leaves us with 3.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 21

On to step 6:
If we divide 30 by 21, we get 1 and a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 22621.0
The remainder is 9 after subtracting 21 from 30.
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 7:
The number 21 fits into 90 4 times, leaving a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 22621.4
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.

On to step 8:
If we divide 60 by 21, we get 2 and a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 22621.42
Subtract 42 from 60 to get 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 9:
When dividing 180 by 21, we get 8 with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 22621.428
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 10:
The number 21 fits into 120 5 times, leaving a remainder of 15.
The next digit of our result is 5. 
Result so far: 22621.4285
The remainder is 15 after subtracting 105 from 120.
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 11:
If we divide 150 by 21, we get 7 and a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 22621.42857
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 12:
When dividing 30 by 21, we get 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 22621.428571
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.

On to step 13:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 22621.4285714
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 14:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 22621.42857142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

The final result is 22621.42857142 with a remainder of 1.8e-08.