We're dividing 421504 by 8 
We want to figure out the number of times 421504 can be divided by 8.

On to step 1:
The number 8 fits into 4 0 times, leaving a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 8

Let's proceed to step 2:
42 divided by 8 is 5 with a remainder of 2.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Subtracting 40 from 42 leaves us with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 8

Going ahead to step 3:
8 can be fit into 21 2 times, resulting in a remainder of 5.
Use 2 as the next digit of our solution. 
Result so far: 52.0
The remainder is 5 after subtracting 16 from 21.
Bring next digit (5) of the dividend behind the 5 and repeat the process: 55 / 8

Let's proceed to step 4:
8 goes into 55 6 times with a remainder of 7.
Use 6 as the next digit of our solution. 
Result so far: 526.0
The remainder is 7 after subtracting 48 from 55.
Fetch the next digit (0) from the dividend, attach it to 7 and continue: 70 / 8

Let's proceed to step 5:
If we divide 70 by 8, we get 8 and a remainder of 6.
Write down 8 as next digit of the result. 
Result so far: 5268.0
Subtracting 64 from 70 leaves us with 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 8

Let's proceed to step 6:
8 can be fit into 64 8 times, resulting in a remainder of 0.
The next digit of our result is 8. 
Result so far: 52688.0
The remainder is 0 after subtracting 64 from 64.
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 7:
8 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 52688.0
Subtracting 0 from 0 leaves us 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.

Advancing to step 8:
If we divide 0 by 8, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 52688.0
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.

Our division results in 52688.0 with a remaining 0.0.