We divide 639740 by 12
Our goal is to divide 639740 by 12.

Going ahead to step 1:
If we divide 6 by 12, we get 0 and a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 12

Step 2:
12 goes into 63 5 times with a remainder of 3.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
If we subtract 60 from 63, we get 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 12

Going ahead to step 3:
12 goes into 39 3 times with a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 53.0
If we subtract 36 from 39, we get 3.
Fetch the next digit (7) from the dividend, attach it to 3 and continue: 37 / 12

On to step 4:
12 goes into 37 3 times with a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 533.0
If we subtract 36 from 37, we get 1.
Fetch the next digit (4) from the dividend, attach it to 1 and continue: 14 / 12

Let's proceed to step 5:
12 can be fit into 14 1 times, resulting in a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 5331.0
If we take 12 away from 14, we end up with 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 12

Step 6:
12 can be fit into 20 1 times, resulting in a remainder of 8.
Write down 1 as next digit of the result. 
Result so far: 53311.0
Deduct 12 from 20 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 7:
12 goes into 80 6 times with a remainder of 8.
Put 6 as the next digit of the answer. 
Result so far: 53311.6
The remainder is 8 after subtracting 72 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 8:
If we divide 80 by 12, we get 6 and a remainder of 8.
The number 6 becomes the next digit in our result. 
Result so far: 53311.66
If we subtract 72 from 80, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final outcome is 53311.66, with a leftover of 0.008.