We're dividing 669851 by 20 
The aim is to understand the frequency of 20 in 669851.

Let's proceed to step 1:
The number 20 fits into 6 0 times, leaving a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 20

Let's proceed to step 2:
66 divided by 20 is 3 with a remainder of 6.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
The remainder is 6 after subtracting 60 from 66.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 20

Advancing to step 3:
20 goes into 69 3 times with a remainder of 9.
Write down 3 as next digit of the result. 
Result so far: 33.0
If we take 60 away from 69, we end up with 9.
Fetch the next digit (8) from the dividend, attach it to 9 and continue: 98 / 20

Advancing to step 4:
20 goes into 98 4 times with a remainder of 18.
Record the quotient 4 as the next digit in the result. 
Result so far: 334.0
Subtracting 80 from 98 leaves us with 18.
Grab the next digit (5) from the dividend, add it to 18, then carry on: 185 / 20

Step 5:
20 goes into 185 9 times with a remainder of 5.
The next digit of our result is 9. 
Result so far: 3349.0
Subtracting 180 from 185 leaves us with 5.
Grab the next digit (1) from the dividend, add it to 5, then carry on: 51 / 20

Moving on to step 6:
The number 20 fits into 51 2 times, leaving a remainder of 11.
Use 2 as the next digit of our solution. 
Result so far: 33492.0
If we subtract 40 from 51, 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.

Going ahead to step 7:
When dividing 110 by 20, we get 5 with a remainder of 10.
The number 5 becomes the next digit in our result. 
Result so far: 33492.5
If we take 100 away from 110, we end up 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.

Let's proceed to step 8:
If we divide 100 by 20, we get 5 and a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 33492.55
Subtract 100 from 100 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 result is 33492.55 with a remainder of 0.0.