We're dividing 12486 by 20 
The aim is to understand the frequency of 20 in 12486.

Advancing to step 1:
1 divided by 20 is 0 with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 20

Let's proceed to step 2:
The number 20 fits into 12 0 times, leaving a remainder of 12.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 12, we get 12.
Append the next digit (4) from the dividend to 12 and continue with: 124 / 20

On to step 3:
If we divide 124 by 20, we get 6 and a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 6.0
Deduct 120 from 124 and we're left with 4.
Append the next digit (8) from the dividend to 4 and continue with: 48 / 20

Advancing to step 4:
20 can be fit into 48 2 times, resulting in a remainder of 8.
The next digit of our result is 2. 
Result so far: 62.0
Subtract 40 from 48 to get 8.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 20

Going ahead to step 5:
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: 624.0
Deduct 80 from 86 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 6:
20 goes into 60 3 times with a remainder of 0.
The next digit of our result is 3. 
Result so far: 624.3
Deduct 60 from 60 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.

Step 7:
0 divided by 20 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 624.3
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.

On to step 8:
20 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 624.3
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 624.3 with a remaining 0.0.