We divide 628643 by 20
The aim is to understand the frequency of 20 in 628643.

Advancing to step 1:
20 goes into 6 0 times with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (2) from the dividend after 6, then repeat: 62 / 20

Advancing to step 2:
20 can be fit into 62 3 times, resulting in a remainder of 2.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Deduct 60 from 62 and we're left with 2.
Bring next digit (8) of the dividend behind the 2 and repeat the process: 28 / 20

Let's proceed to step 3:
When dividing 28 by 20, we get 1 with a remainder of 8.
Use 1 as the next digit of our solution. 
Result so far: 31.0
The remainder is 8 after subtracting 20 from 28.
Fetch the next digit (6) from the dividend, attach it to 8 and continue: 86 / 20

Let's proceed to step 4:
86 divided by 20 is 4 with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 314.0
If we take 80 away from 86, we end up with 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 20

On to step 5:
If we divide 64 by 20, we get 3 and a remainder of 4.
The next digit of our result is 3. 
Result so far: 3143.0
The remainder is 4 after subtracting 60 from 64.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 20

On to step 6:
43 divided by 20 is 2 with a remainder of 3.
The next digit of our result is 2. 
Result so far: 31432.0
If we take 40 away from 43, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 7:
20 goes into 30 1 times with a remainder of 10.
Write down 1 as next digit of the result. 
Result so far: 31432.1
Subtracting 20 from 30 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 8:
When dividing 100 by 20, we get 5 with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 31432.15
Deduct 100 from 100 and we're left 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.

On to step 9:
When dividing 0 by 20, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 31432.15
Deduct 0 from 0 and we're left 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.

Moving on to step 10:
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: 31432.15
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.

The final result is 31432.15 with a remainder of 0.0.