We look at the division of 391638 by 8 
We want to figure out the number of times 391638 can be divided by 8.

On to step 1:
8 can be fit into 3 0 times, resulting in a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 8

Going ahead to step 2:
When dividing 39 by 8, we get 4 with a remainder of 7.
Write down 4 as next digit of the result. 
Result so far: 4.0
Subtracting 32 from 39 leaves us with 7.
Grab the next digit (1) from the dividend, add it to 7, then carry on: 71 / 8

Step 3:
71 divided by 8 is 8 with a remainder of 7.
Write down 8 as next digit of the result. 
Result so far: 48.0
Deduct 64 from 71 and we're left with 7.
Fetch the next digit (6) from the dividend, attach it to 7 and continue: 76 / 8

Step 4:
The number 8 fits into 76 9 times, leaving a remainder of 4.
Put 9 as the next digit of the answer. 
Result so far: 489.0
The remainder is 4 after subtracting 72 from 76.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 8

On to step 5:
8 can be fit into 43 5 times, resulting in a remainder of 3.
Write down 5 as next digit of the result. 
Result so far: 4895.0
If we take 40 away from 43, we end up with 3.
Append the next digit (8) from the dividend to 3 and continue with: 38 / 8

Going ahead to step 6:
8 goes into 38 4 times with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 48954.0
Subtracting 32 from 38 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 7:
8 can be fit into 60 7 times, resulting in a remainder of 4.
Use 7 as the next digit of our solution. 
Result so far: 48954.7
If we subtract 56 from 60, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 8:
The number 8 fits into 40 5 times, leaving a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 48954.75
If we take 40 away from 40, 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.

Going ahead to step 9:
When dividing 0 by 8, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 48954.75
Subtract 0 from 0 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.

Step 10:
8 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 48954.75
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 48954.75 and a remainder of 0.0.