We're dividing 839246 by 21 
The aim is to understand the frequency of 21 in 839246.

On to step 1:
The number 21 fits into 8 0 times, leaving a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (3) from the dividend, attach it to 8 and continue: 83 / 21

Advancing to step 2:
If we divide 83 by 21, we get 3 and a remainder of 20.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 63 from 83 leaves us with 20.
Include the next digit (9) from the dividend after 20, then repeat: 209 / 21

Advancing to step 3:
If we divide 209 by 21, we get 9 and a remainder of 20.
The next digit of our result is 9. 
Result so far: 39.0
Deduct 189 from 209 and we're left with 20.
Bring next digit (2) of the dividend behind the 20 and repeat the process: 202 / 21

On to step 4:
If we divide 202 by 21, we get 9 and a remainder of 13.
Put 9 as the next digit of the answer. 
Result so far: 399.0
Deduct 189 from 202 and we're left with 13.
Take the next digit (4) from the dividend and append it to 13, then repeat: 134 / 21

Let's proceed to step 5:
21 can be fit into 134 6 times, resulting in a remainder of 8.
Write down 6 as next digit of the result. 
Result so far: 3996.0
Deduct 126 from 134 and we're left with 8.
Fetch the next digit (6) from the dividend, attach it to 8 and continue: 86 / 21

Moving on to step 6:
The number 21 fits into 86 4 times, leaving a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 39964.0
Subtracting 84 from 86 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.

Advancing to step 7:
The number 21 fits into 20 0 times, leaving a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 39964.0
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 8:
When dividing 200 by 21, we get 9 with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 39964.09
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.

Step 9:
If we divide 110 by 21, we get 5 and a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 39964.095
Deduct 105 from 110 and we're left 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.

Moving on to step 10:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 39964.0952
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.

Let's proceed to step 11:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 39964.09523
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 12:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 39964.095238
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 13:
If we divide 20 by 21, we get 0 and a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 39964.095238
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 14:
When dividing 200 by 21, we get 9 with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 39964.09523809
Deduct 189 from 200 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

The quotient of the division is 39964.09523809, and the remainder is 1.1e-08.