644436 ÷ 20 
The aim is to understand the frequency of 20 in 644436.

Moving on to step 1:
The number 20 fits into 6 0 times, leaving a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 20

Let's proceed to step 2:
The number 20 fits into 64 3 times, leaving a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 3.0
The remainder is 4 after subtracting 60 from 64.
Fetch the next digit (4) from the dividend, attach it to 4 and continue: 44 / 20

Advancing to step 3:
44 divided by 20 is 2 with a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 32.0
If we take 40 away from 44, we end up with 4.
Fetch the next digit (4) from the dividend, attach it to 4 and continue: 44 / 20

Advancing to step 4:
20 goes into 44 2 times with a remainder of 4.
Use 2 as the next digit of our solution. 
Result so far: 322.0
If we subtract 40 from 44, we get 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 20

Let's proceed to step 5:
The number 20 fits into 43 2 times, leaving a remainder of 3.
Use 2 as the next digit of our solution. 
Result so far: 3222.0
If we subtract 40 from 43, we get 3.
Grab the next digit (6) from the dividend, add it to 3, then carry on: 36 / 20

Advancing to step 6:
20 goes into 36 1 times with a remainder of 16.
The number 1 becomes the next digit in our result. 
Result so far: 32221.0
If we take 20 away from 36, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 7:
20 goes into 160 8 times with a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 32221.8
Subtracting 160 from 160 leaves us 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 8:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 32221.8
Subtract 0 from 0 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.

Let's proceed to step 9:
0 divided by 20 is 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 32221.8
Subtract 0 from 0 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.

The final outcome is 32221.8, with a leftover of 0.0.