We're dividing 720171 by 18 
Let's see how many times 18 fits into 720171.

Advancing to step 1:
When dividing 7 by 18, we get 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Bring next digit (2) of the dividend behind the 7 and repeat the process: 72 / 18

On to step 2:
72 divided by 18 is 4 with a remainder of 0.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we take 72 away from 72, we end up with 0.
Grab the next digit (0) from the dividend, add it to 0, then carry on: 0 / 18

Step 3:
If we divide 0 by 18, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 40.0
Subtracting 0 from 0 leaves us with 0.
Include the next digit (1) from the dividend after 0, then repeat: 1 / 18

On to step 4:
1 divided by 18 is 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 400.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 18

On to step 5:
If we divide 17 by 18, we get 0 and a remainder of 17.
The number 0 becomes the next digit in our result. 
Result so far: 4000.0
If we take 0 away from 17, we end up with 17.
Take the next digit (1) from the dividend and append it to 17, then repeat: 171 / 18

Going ahead to step 6:
18 can be fit into 171 9 times, resulting in a remainder of 9.
Record the quotient 9 as the next digit in the result. 
Result so far: 40009.0
If we take 162 away from 171, we end up 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.

Advancing to step 7:
If we divide 90 by 18, we get 5 and a remainder of 0.
The next digit of our result is 5. 
Result so far: 40009.5
Subtract 90 from 90 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.

Moving on to step 8:
0 divided by 18 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 40009.5
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 9:
If we divide 0 by 18, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 40009.5
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.

The final outcome is 40009.5, with a leftover of 0.0.