640218 ÷ 20 
The aim is to understand the frequency of 20 in 640218.

Advancing to step 1:
When dividing 6 by 20, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 20

Advancing to step 2:
20 goes into 64 3 times with a remainder of 4.
The next digit of our result is 3. 
Result so far: 3.0
Subtract 60 from 64 to get 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 20

Moving on to step 3:
The number 20 fits into 40 2 times, leaving a remainder of 0.
Write down 2 as next digit of the result. 
Result so far: 32.0
Deduct 40 from 40 and we're left with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 20

Moving on to step 4:
20 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 320.0
Subtracting 0 from 2 leaves us with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 20

On to step 5:
20 can be fit into 21 1 times, resulting in a remainder of 1.
Write down 1 as next digit of the result. 
Result so far: 3201.0
If we subtract 20 from 21, we get 1.
Append the next digit (8) from the dividend to 1 and continue with: 18 / 20

Step 6:
20 can be fit into 18 0 times, resulting in a remainder of 18.
Put 0 as the next digit of the answer. 
Result so far: 32010.0
Subtracting 0 from 18 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 7:
180 divided by 20 is 9 with a remainder of 0.
The next digit of our result is 9. 
Result so far: 32010.9
Subtract 180 from 180 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.

Moving on to step 8:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 32010.9
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 9:
If we divide 0 by 20, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 32010.9
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 outcome is 32010.9, with a leftover of 0.0.