323735 divided by 21 
The aim is to understand the frequency of 21 in 323735.

Step 1:
3 divided by 21 is 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (2) from the dividend, attach it to 3 and continue: 32 / 21

Let's proceed to step 2:
21 can be fit into 32 1 times, resulting in a remainder of 11.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 21 from 32 and we're left with 11.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 21

Going ahead to step 3:
When dividing 113 by 21, we get 5 with a remainder of 8.
The next digit of our result is 5. 
Result so far: 15.0
Subtracting 105 from 113 leaves us with 8.
Grab the next digit (7) from the dividend, add it to 8, then carry on: 87 / 21

Advancing to step 4:
The number 21 fits into 87 4 times, leaving a remainder of 3.
Put 4 as the next digit of the answer. 
Result so far: 154.0
Subtract 84 from 87 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 21

On to step 5:
33 divided by 21 is 1 with a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 1541.0
The remainder is 12 after subtracting 21 from 33.
Fetch the next digit (5) from the dividend, attach it to 12 and continue: 125 / 21

Moving on to step 6:
If we divide 125 by 21, we get 5 and a remainder of 20.
The next digit of our result is 5. 
Result so far: 15415.0
Deduct 105 from 125 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.

Step 7:
200 divided by 21 is 9 with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 15415.9
Subtract 189 from 200 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.

Moving on to step 8:
If we divide 110 by 21, we get 5 and a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 15415.95
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.

On to step 9:
When dividing 50 by 21, we get 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 15415.952
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 10:
21 goes into 80 3 times with a remainder of 17.
The next digit of our result is 3. 
Result so far: 15415.9523
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 11:
When dividing 170 by 21, we get 8 with a remainder of 2.
The next digit of our result is 8. 
Result so far: 15415.95238
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.

Step 12:
20 divided by 21 is 0 with a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 15415.95238
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.

On to step 13:
21 can be fit into 200 9 times, resulting in a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 15415.9523809
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.

Going ahead to step 14:
If we divide 110 by 21, we get 5 and a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 15415.95238095
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.

The final result is 15415.95238095 with a remainder of 5e-09.