We look at the division of 935226 by 21 
The aim is to understand the frequency of 21 in 935226.

Step 1:
If we divide 9 by 21, we get 0 and a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Include the next digit (3) from the dividend after 9, then repeat: 93 / 21

Moving on to step 2:
21 can be fit into 93 4 times, resulting in a remainder of 9.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtracting 84 from 93 leaves us with 9.
Fetch the next digit (5) from the dividend, attach it to 9 and continue: 95 / 21

Step 3:
21 can be fit into 95 4 times, resulting in a remainder of 11.
The number 4 becomes the next digit in our result. 
Result so far: 44.0
If we take 84 away from 95, we end up with 11.
Include the next digit (2) from the dividend after 11, then repeat: 112 / 21

On to step 4:
The number 21 fits into 112 5 times, leaving a remainder of 7.
Record the quotient 5 as the next digit in the result. 
Result so far: 445.0
If we take 105 away from 112, we end up with 7.
Bring next digit (2) of the dividend behind the 7 and repeat the process: 72 / 21

Moving on to step 5:
21 goes into 72 3 times with a remainder of 9.
The number 3 becomes the next digit in our result. 
Result so far: 4453.0
Subtract 63 from 72 to get 9.
Include the next digit (6) from the dividend after 9, then repeat: 96 / 21

Moving on to step 6:
96 divided by 21 is 4 with a remainder of 12.
Write down 4 as next digit of the result. 
Result so far: 44534.0
The remainder is 12 after subtracting 84 from 96.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 7:
If we divide 120 by 21, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 44534.5
Deduct 105 from 120 and we're left with 15.
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 8:
150 divided by 21 is 7 with a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 44534.57
If we take 147 away from 150, we end up 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.

Step 9:
30 divided by 21 is 1 with a remainder of 9.
The next digit of our result is 1. 
Result so far: 44534.571
Subtracting 21 from 30 leaves us 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.

Advancing to step 10:
If we divide 90 by 21, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 44534.5714
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.

Going ahead to step 11:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 44534.57142
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.

Moving on 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: 44534.571428
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.

Moving on to step 13:
When dividing 120 by 21, we get 5 with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 44534.5714285
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.

Advancing to step 14:
21 goes into 150 7 times with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 44534.57142857
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.

In conclusion, the division gives 44534.57142857 with a balance of 3e-09.