We're dividing 126489 by 20 
We want to figure out the number of times 126489 can be divided by 20.

Going ahead to step 1:
When dividing 1 by 20, we get 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 20

Step 2:
If we divide 12 by 20, we get 0 and a remainder of 12.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Grab the next digit (6) from the dividend, add it to 12, then carry on: 126 / 20

Step 3:
20 goes into 126 6 times with a remainder of 6.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
Deduct 120 from 126 and we're left with 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 20

Moving on to step 4:
20 goes into 64 3 times with a remainder of 4.
The number 3 becomes the next digit in our result. 
Result so far: 63.0
Deduct 60 from 64 and we're left with 4.
Grab the next digit (8) from the dividend, add it to 4, then carry on: 48 / 20

Advancing to step 5:
When dividing 48 by 20, we get 2 with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 632.0
Deduct 40 from 48 and we're left with 8.
Append the next digit (9) from the dividend to 8 and continue with: 89 / 20

Let's proceed to step 6:
If we divide 89 by 20, we get 4 and a remainder of 9.
Put 4 as the next digit of the answer. 
Result so far: 6324.0
Deduct 80 from 89 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 7:
20 goes into 90 4 times with a remainder of 10.
Use 4 as the next digit of our solution. 
Result so far: 6324.4
Deduct 80 from 90 and we're left 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:
20 can be fit into 100 5 times, resulting in a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 6324.45
Subtracting 100 from 100 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.

Let's proceed to step 9:
20 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 6324.45
The remainder is 0 after subtracting 0 from 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:
0 divided by 20 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 6324.45
Subtracting 0 from 0 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.

The quotient of the division is 6324.45, and the remainder is 0.0.