835979 ÷ 21 
The aim is to understand the frequency of 21 in 835979.

Advancing to step 1:
21 can be fit into 8 0 times, resulting in a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Fetch the next digit (3) from the dividend, attach it to 8 and continue: 83 / 21

Advancing to step 2:
The number 21 fits into 83 3 times, leaving a remainder of 20.
The next digit of our result is 3. 
Result so far: 3.0
If we take 63 away from 83, we end up with 20.
Fetch the next digit (5) from the dividend, attach it to 20 and continue: 205 / 21

Advancing to step 3:
If we divide 205 by 21, we get 9 and a remainder of 16.
Record the quotient 9 as the next digit in the result. 
Result so far: 39.0
Subtract 189 from 205 to get 16.
Bring next digit (9) of the dividend behind the 16 and repeat the process: 169 / 21

Let's proceed to step 4:
21 can be fit into 169 8 times, resulting in a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 398.0
Subtracting 168 from 169 leaves us with 1.
Take the next digit (7) from the dividend and append it to 1, then repeat: 17 / 21

Advancing to step 5:
When dividing 17 by 21, we get 0 with a remainder of 17.
Write down 0 as next digit of the result. 
Result so far: 3980.0
Subtract 0 from 17 to get 17.
Fetch the next digit (9) from the dividend, attach it to 17 and continue: 179 / 21

Moving on to step 6:
21 goes into 179 8 times with a remainder of 11.
The next digit of our result is 8. 
Result so far: 39808.0
Subtract 168 from 179 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 7:
110 divided by 21 is 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 39808.5
If we take 105 away from 110, we end up 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.

On to step 8:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 39808.52
Deduct 42 from 50 and we're left 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 9:
80 divided by 21 is 3 with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 39808.523
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 10:
21 goes into 170 8 times with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 39808.5238
If we subtract 168 from 170, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 11:
When dividing 20 by 21, we get 0 with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 39808.5238
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.

On to step 12:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 39808.523809
If we subtract 189 from 200, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 13:
110 divided by 21 is 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 39808.5238095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 14:
21 goes into 50 2 times with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 39808.52380952
Subtract 42 from 50 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The quotient of the division is 39808.52380952, and the remainder is 8e-09.