We're dividing 115406 by 21 
The aim is to understand the frequency of 21 in 115406.

Advancing to step 1:
1 divided by 21 is 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Fetch the next digit (1) from the dividend, attach it to 1 and continue: 11 / 21

Going ahead to step 2:
21 goes into 11 0 times with a remainder of 11.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 11 and we're left with 11.
Bring next digit (5) of the dividend behind the 11 and repeat the process: 115 / 21

Going ahead to step 3:
115 divided by 21 is 5 with a remainder of 10.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Deduct 105 from 115 and we're left with 10.
Take the next digit (4) from the dividend and append it to 10, then repeat: 104 / 21

Let's proceed to step 4:
If we divide 104 by 21, we get 4 and a remainder of 20.
Record the quotient 4 as the next digit in the result. 
Result so far: 54.0
Deduct 84 from 104 and we're left with 20.
Grab the next digit (0) from the dividend, add it to 20, then carry on: 200 / 21

Step 5:
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: 549.0
Subtracting 189 from 200 leaves us with 11.
Take the next digit (6) from the dividend and append it to 11, then repeat: 116 / 21

On to step 6:
If we divide 116 by 21, we get 5 and a remainder of 11.
Write down 5 as next digit of the result. 
Result so far: 5495.0
If we subtract 105 from 116, 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.

Advancing to step 7:
21 goes into 110 5 times with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 5495.5
Subtracting 105 from 110 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.

Step 8:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 5495.52
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.

On to step 9:
The number 21 fits into 80 3 times, leaving a remainder of 17.
The next digit of our result is 3. 
Result so far: 5495.523
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.

Moving on to step 10:
When dividing 170 by 21, we get 8 with a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 5495.5238
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.

Advancing to step 11:
21 goes into 20 0 times with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 5495.5238
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.

Let's proceed to step 12:
If we divide 200 by 21, we get 9 and a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 5495.523809
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.

On to step 13:
When dividing 110 by 21, we get 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 5495.5238095
Subtracting 105 from 110 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.

Going ahead to step 14:
If we divide 50 by 21, we get 2 and a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 5495.52380952
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.

The quotient of the division is 5495.52380952, and the remainder is 8e-09.