639423 ÷ 4 
We want to divide 639423 by 4.

Moving on to step 1:
If we divide 6 by 4, we get 1 and a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 4 from 6, we get 2.
Include the next digit (3) from the dividend after 2, then repeat: 23 / 4

Let's proceed to step 2:
If we divide 23 by 4, we get 5 and a remainder of 3.
Put 5 as the next digit of the answer. 
Result so far: 15.0
Subtract 20 from 23 to get 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 4

Moving on to step 3:
4 goes into 39 9 times with a remainder of 3.
Write down 9 as next digit of the result. 
Result so far: 159.0
If we take 36 away from 39, we end up with 3.
Append the next digit (4) from the dividend to 3 and continue with: 34 / 4

Going ahead to step 4:
The number 4 fits into 34 8 times, leaving a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 1598.0
Deduct 32 from 34 and we're left with 2.
Fetch the next digit (2) from the dividend, attach it to 2 and continue: 22 / 4

Step 5:
4 goes into 22 5 times with a remainder of 2.
Put 5 as the next digit of the answer. 
Result so far: 15985.0
The remainder is 2 after subtracting 20 from 22.
Grab the next digit (3) from the dividend, add it to 2, then carry on: 23 / 4

Going ahead to step 6:
23 divided by 4 is 5 with a remainder of 3.
Use 5 as the next digit of our solution. 
Result so far: 159855.0
Deduct 20 from 23 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 7:
4 goes into 30 7 times with a remainder of 2.
Record the quotient 7 as the next digit in the result. 
Result so far: 159855.7
Deduct 28 from 30 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 8:
20 divided by 4 is 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 159855.75
If we subtract 20 from 20, 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.

Let's proceed to step 9:
4 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 159855.75
If we subtract 0 from 0, 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.

Advancing to step 10:
4 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 159855.75
If we subtract 0 from 0, 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.

Our division results in 159855.75 with a remaining 0.0.