533055 divided by 21 
The aim is to understand the frequency of 21 in 533055.

Step 1:
21 goes into 5 0 times with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Include the next digit (3) from the dividend after 5, then repeat: 53 / 21

Moving on to step 2:
53 divided by 21 is 2 with a remainder of 11.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we subtract 42 from 53, we get 11.
Fetch the next digit (3) from the dividend, attach it to 11 and continue: 113 / 21

Let's proceed to step 3:
If we divide 113 by 21, we get 5 and a remainder of 8.
Write down 5 as next digit of the result. 
Result so far: 25.0
Subtracting 105 from 113 leaves us with 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 21

Step 4:
21 goes into 80 3 times with a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 253.0
Subtracting 63 from 80 leaves us with 17.
Take the next digit (5) from the dividend and append it to 17, then repeat: 175 / 21

On to step 5:
If we divide 175 by 21, we get 8 and a remainder of 7.
Put 8 as the next digit of the answer. 
Result so far: 2538.0
If we take 168 away from 175, we end up with 7.
Include the next digit (5) from the dividend after 7, then repeat: 75 / 21

Advancing to step 6:
When dividing 75 by 21, we get 3 with a remainder of 12.
Record the quotient 3 as the next digit in the result. 
Result so far: 25383.0
Deduct 63 from 75 and we're left 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.

Let's proceed to step 7:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 25383.5
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.

On to step 8:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 25383.57
The remainder is 3 after subtracting 147 from 150.
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 9:
30 divided by 21 is 1 with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 25383.571
Deduct 21 from 30 and we're left 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.

Step 10:
When dividing 90 by 21, we get 4 with a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 25383.5714
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.

Step 11:
When dividing 60 by 21, we get 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 25383.57142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 12:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 25383.571428
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.

On to step 13:
If we divide 120 by 21, we get 5 and a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 25383.5714285
If we subtract 105 from 120, we 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.

Step 14:
The number 21 fits into 150 7 times, leaving a remainder of 3.
The next digit of our result is 7. 
Result so far: 25383.57142857
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.

The final result is 25383.57142857 with a remainder of 3e-09.