418856 ÷ 21 
The aim is to understand the frequency of 21 in 418856.

Step 1:
4 divided by 21 is 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Bring next digit (1) of the dividend behind the 4 and repeat the process: 41 / 21

Moving on to step 2:
41 divided by 21 is 1 with a remainder of 20.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtract 21 from 41 to get 20.
Bring next digit (8) of the dividend behind the 20 and repeat the process: 208 / 21

Advancing to step 3:
If we divide 208 by 21, we get 9 and a remainder of 19.
Put 9 as the next digit of the answer. 
Result so far: 19.0
If we take 189 away from 208, we end up with 19.
Include the next digit (8) from the dividend after 19, then repeat: 198 / 21

Let's proceed to step 4:
When dividing 198 by 21, we get 9 with a remainder of 9.
Write down 9 as next digit of the result. 
Result so far: 199.0
Subtract 189 from 198 to get 9.
Include the next digit (5) from the dividend after 9, then repeat: 95 / 21

Let's proceed to step 5:
When dividing 95 by 21, we get 4 with a remainder of 11.
Use 4 as the next digit of our solution. 
Result so far: 1994.0
Subtract 84 from 95 to get 11.
Grab the next digit (6) from the dividend, add it to 11, then carry on: 116 / 21

On to step 6:
If we divide 116 by 21, we get 5 and a remainder of 11.
The next digit of our result is 5. 
Result so far: 19945.0
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.

Let's proceed to step 7:
If we divide 110 by 21, we get 5 and a remainder of 5.
The next digit of our result is 5. 
Result so far: 19945.5
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.

Step 8:
21 goes into 50 2 times with a remainder of 8.
The next digit of our result is 2. 
Result so far: 19945.52
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.

Going ahead to step 9:
21 goes into 80 3 times with a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 19945.523
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.

Step 10:
21 goes into 170 8 times with a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 19945.5238
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.

Advancing to step 11:
20 divided by 21 is 0 with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 19945.5238
Subtract 0 from 20 to 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.

Going ahead to step 12:
200 divided by 21 is 9 with a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 19945.523809
If we take 189 away from 200, we end up 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:
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: 19945.5238095
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 14:
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: 19945.52380952
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.

After the division, we end up with 19945.52380952 and a remainder of 8e-09.