We divide 856404 by 20
The aim is to understand the frequency of 20 in 856404.

On to step 1:
When dividing 8 by 20, we get 0 with 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.
Take the next digit (5) from the dividend and append it to 8, then repeat: 85 / 20

Step 2:
20 can be fit into 85 4 times, resulting in a remainder of 5.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Deduct 80 from 85 and we're left with 5.
Append the next digit (6) from the dividend to 5 and continue with: 56 / 20

Let's proceed to step 3:
When dividing 56 by 20, we get 2 with a remainder of 16.
Record the quotient 2 as the next digit in the result. 
Result so far: 42.0
The remainder is 16 after subtracting 40 from 56.
Append the next digit (4) from the dividend to 16 and continue with: 164 / 20

Step 4:
When dividing 164 by 20, we get 8 with a remainder of 4.
Put 8 as the next digit of the answer. 
Result so far: 428.0
Subtract 160 from 164 to get 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 20

Advancing to step 5:
When dividing 40 by 20, we get 2 with a remainder of 0.
Write down 2 as next digit of the result. 
Result so far: 4282.0
If we subtract 40 from 40, we get 0.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 20

Let's proceed to step 6:
When dividing 4 by 20, we get 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 42820.0
Deduct 0 from 4 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 7:
If we divide 40 by 20, we get 2 and a remainder of 0.
The next digit of our result is 2. 
Result so far: 42820.2
Subtract 40 from 40 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 8:
20 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 42820.2
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 9:
If we divide 0 by 20, we get 0 and a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 42820.2
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 42820.2 with a remainder of 0.0.