66637824 divided by 20 
The aim is to understand the frequency of 20 in 66637824.

Going ahead to step 1:
6 divided by 20 is 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 20

On 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
If we subtract 60 from 66, we get 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 20

Going ahead to step 3:
If we divide 66 by 20, we get 3 and a remainder of 6.
Use 3 as the next digit of our solution. 
Result so far: 33.0
Subtract 60 from 66 to get 6.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 20

Moving on to step 4:
When dividing 63 by 20, we get 3 with a remainder of 3.
Record the quotient 3 as the next digit in the result. 
Result so far: 333.0
The remainder is 3 after subtracting 60 from 63.
Append the next digit (7) from the dividend to 3 and continue with: 37 / 20

On to step 5:
When dividing 37 by 20, we get 1 with a remainder of 17.
Put 1 as the next digit of the answer. 
Result so far: 3331.0
The remainder is 17 after subtracting 20 from 37.
Grab the next digit (8) from the dividend, add it to 17, then carry on: 178 / 20

On to step 6:
178 divided by 20 is 8 with a remainder of 18.
Record the quotient 8 as the next digit in the result. 
Result so far: 33318.0
Subtract 160 from 178 to get 18.
Fetch the next digit (2) from the dividend, attach it to 18 and continue: 182 / 20

Let's proceed to step 7:
20 can be fit into 182 9 times, resulting in a remainder of 2.
Use 9 as the next digit of our solution. 
Result so far: 333189.0
Subtracting 180 from 182 leaves us with 2.
Take the next digit (4) from the dividend and append it to 2, then repeat: 24 / 20

Advancing to step 8:
The number 20 fits into 24 1 times, leaving a remainder of 4.
The next digit of our result is 1. 
Result so far: 3331891.0
Deduct 20 from 24 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.

Step 9:
When dividing 40 by 20, we get 2 with a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 3331891.2
If we subtract 40 from 40, 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.

Advancing to step 10:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 3331891.2
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.

Advancing to step 11:
20 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 3331891.2
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.

Our division results in 3331891.2 with a remaining 0.0.