We're dividing 63990731 by 18 
We want to figure out the number of times 63990731 can be divided by 18.

Moving on to step 1:
If we divide 6 by 18, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 18

On to step 2:
63 divided by 18 is 3 with a remainder of 9.
Use 3 as the next digit of our solution. 
Result so far: 3.0
If we take 54 away from 63, we end up with 9.
Bring next digit (9) of the dividend behind the 9 and repeat the process: 99 / 18

Moving on to step 3:
If we divide 99 by 18, we get 5 and a remainder of 9.
The next digit of our result is 5. 
Result so far: 35.0
The remainder is 9 after subtracting 90 from 99.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 18

Moving on to step 4:
18 goes into 99 5 times with a remainder of 9.
The next digit of our result is 5. 
Result so far: 355.0
If we take 90 away from 99, we end up with 9.
Include the next digit (0) from the dividend after 9, then repeat: 90 / 18

On to step 5:
When dividing 90 by 18, we get 5 with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 3555.0
If we take 90 away from 90, we end up with 0.
Fetch the next digit (7) from the dividend, attach it to 0 and continue: 7 / 18

Going ahead to step 6:
The number 18 fits into 7 0 times, leaving a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 35550.0
Subtracting 0 from 7 leaves us with 7.
Bring next digit (3) of the dividend behind the 7 and repeat the process: 73 / 18

Moving on to step 7:
73 divided by 18 is 4 with a remainder of 1.
The number 4 becomes the next digit in our result. 
Result so far: 355504.0
Subtract 72 from 73 to get 1.
Take the next digit (1) from the dividend and append it to 1, then repeat: 11 / 18

On to step 8:
18 goes into 11 0 times with a remainder of 11.
Use 0 as the next digit of our solution. 
Result so far: 3555040.0
If we subtract 0 from 11, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Let's proceed to step 9:
When dividing 110 by 18, we get 6 with a remainder of 2.
Use 6 as the next digit of our solution. 
Result so far: 3555040.6
If we subtract 108 from 110, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 10:
The number 18 fits into 20 1 times, leaving a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 3555040.61
Subtract 18 from 20 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 11:
18 can be fit into 20 1 times, resulting in a remainder of 2.
Write down 1 as next digit of the result. 
Result so far: 3555040.611
Subtract 18 from 20 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final outcome is 3555040.611, with a leftover of 0.0002.