We look at the division of 138945 by 20 
We want to figure out the number of times 138945 can be divided by 20.

Moving on to step 1:
When dividing 1 by 20, we get 0 with a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 20

On to step 2:
When dividing 13 by 20, we get 0 with a remainder of 13.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 13 after subtracting 0 from 13.
Take the next digit (8) from the dividend and append it to 13, then repeat: 138 / 20

On to step 3:
If we divide 138 by 20, we get 6 and a remainder of 18.
Use 6 as the next digit of our solution. 
Result so far: 6.0
The remainder is 18 after subtracting 120 from 138.
Append the next digit (9) from the dividend to 18 and continue with: 189 / 20

Moving on to step 4:
The number 20 fits into 189 9 times, leaving a remainder of 9.
The number 9 becomes the next digit in our result. 
Result so far: 69.0
Deduct 180 from 189 and we're left with 9.
Include the next digit (4) from the dividend after 9, then repeat: 94 / 20

Step 5:
20 goes into 94 4 times with a remainder of 14.
Put 4 as the next digit of the answer. 
Result so far: 694.0
If we subtract 80 from 94, we get 14.
Take the next digit (5) from the dividend and append it to 14, then repeat: 145 / 20

Advancing to step 6:
20 goes into 145 7 times with a remainder of 5.
Write down 7 as next digit of the result. 
Result so far: 6947.0
Deduct 140 from 145 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 7:
20 can be fit into 50 2 times, resulting in a remainder of 10.
Record the quotient 2 as the next digit in the result. 
Result so far: 6947.2
If we take 40 away from 50, 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.

Step 8:
When dividing 100 by 20, we get 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 6947.25
If we subtract 100 from 100, 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.

On to step 9:
0 divided by 20 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 6947.25
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.

Moving on to step 10:
0 divided by 20 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 6947.25
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.

The quotient of the division is 6947.25, and the remainder is 0.0.