We look at the division of 556112 by 21 
The aim is to understand the frequency of 21 in 556112.

Moving on to step 1:
21 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Take the next digit (5) from the dividend and append it to 5, then repeat: 55 / 21

Let's proceed to step 2:
21 can be fit into 55 2 times, resulting in a remainder of 13.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 42 away from 55, we end up with 13.
Fetch the next digit (6) from the dividend, attach it to 13 and continue: 136 / 21

Step 3:
The number 21 fits into 136 6 times, leaving a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 26.0
Subtracting 126 from 136 leaves us with 10.
Grab the next digit (1) from the dividend, add it to 10, then carry on: 101 / 21

Step 4:
21 goes into 101 4 times with a remainder of 17.
Use 4 as the next digit of our solution. 
Result so far: 264.0
The remainder is 17 after subtracting 84 from 101.
Include the next digit (1) from the dividend after 17, then repeat: 171 / 21

Step 5:
If we divide 171 by 21, we get 8 and a remainder of 3.
The number 8 becomes the next digit in our result. 
Result so far: 2648.0
If we take 168 away from 171, we end up with 3.
Bring next digit (2) of the dividend behind the 3 and repeat the process: 32 / 21

Step 6:
21 can be fit into 32 1 times, resulting in a remainder of 11.
Record the quotient 1 as the next digit in the result. 
Result so far: 26481.0
Deduct 21 from 32 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 7:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 26481.5
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.

Let's proceed to step 8:
21 goes into 50 2 times with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 26481.52
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.

Step 9:
If we divide 80 by 21, we get 3 and a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 26481.523
Subtract 63 from 80 to 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.

Step 10:
If we divide 170 by 21, we get 8 and a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 26481.5238
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.

Step 11:
When dividing 20 by 21, we get 0 with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 26481.5238
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.

Going ahead to step 12:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 26481.523809
Subtracting 189 from 200 leaves us 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.

Moving on to step 13:
110 divided by 21 is 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 26481.5238095
Subtract 105 from 110 to 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.

Step 14:
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: 26481.52380952
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.

The final outcome is 26481.52380952, with a leftover of 8e-09.