We look at the division of 833474 by 21 
The aim is to understand the frequency of 21 in 833474.

Going ahead to step 1:
The number 21 fits into 8 0 times, leaving a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Bring next digit (3) of the dividend behind the 8 and repeat the process: 83 / 21

Moving on to step 2:
83 divided by 21 is 3 with a remainder of 20.
Use 3 as the next digit of our solution. 
Result so far: 3.0
The remainder is 20 after subtracting 63 from 83.
Include the next digit (3) from the dividend after 20, then repeat: 203 / 21

Step 3:
The number 21 fits into 203 9 times, leaving a remainder of 14.
The next digit of our result is 9. 
Result so far: 39.0
If we subtract 189 from 203, we get 14.
Include the next digit (4) from the dividend after 14, then repeat: 144 / 21

Step 4:
If we divide 144 by 21, we get 6 and a remainder of 18.
Put 6 as the next digit of the answer. 
Result so far: 396.0
The remainder is 18 after subtracting 126 from 144.
Fetch the next digit (7) from the dividend, attach it to 18 and continue: 187 / 21

Going ahead to step 5:
When dividing 187 by 21, we get 8 with a remainder of 19.
The next digit of our result is 8. 
Result so far: 3968.0
Subtract 168 from 187 to get 19.
Bring next digit (4) of the dividend behind the 19 and repeat the process: 194 / 21

On to step 6:
194 divided by 21 is 9 with a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 39689.0
Subtracting 189 from 194 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 7:
21 goes into 50 2 times with a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 39689.2
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 8:
21 can be fit into 80 3 times, resulting in a remainder of 17.
The next digit of our result is 3. 
Result so far: 39689.23
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 9:
21 can be fit into 170 8 times, resulting in a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 39689.238
Subtracting 168 from 170 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 10:
21 goes into 20 0 times with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 39689.238
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 11:
When dividing 200 by 21, we get 9 with a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 39689.23809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 12:
If we divide 110 by 21, we get 5 and a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 39689.238095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 13:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 39689.2380952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 14:
If we divide 80 by 21, we get 3 and a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 39689.23809523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

In conclusion, the division gives 39689.23809523 with a balance of 1.7e-08.