668643 ÷ 87 
We're looking to find how many times 87 goes into 668643.

Going ahead to step 1:
87 goes into 6 0 times with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 87

Step 2:
The number 87 fits into 66 0 times, leaving a remainder of 66.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Grab the next digit (8) from the dividend, add it to 66, then carry on: 668 / 87

Step 3:
The number 87 fits into 668 7 times, leaving a remainder of 59.
Use 7 as the next digit of our solution. 
Result so far: 7.0
Deduct 609 from 668 and we're left with 59.
Take the next digit (6) from the dividend and append it to 59, then repeat: 596 / 87

Let's proceed to step 4:
87 can be fit into 596 6 times, resulting in a remainder of 74.
The number 6 becomes the next digit in our result. 
Result so far: 76.0
If we take 522 away from 596, we end up with 74.
Include the next digit (4) from the dividend after 74, then repeat: 744 / 87

Advancing to step 5:
The number 87 fits into 744 8 times, leaving a remainder of 48.
The next digit of our result is 8. 
Result so far: 768.0
Subtracting 696 from 744 leaves us with 48.
Take the next digit (3) from the dividend and append it to 48, then repeat: 483 / 87

Moving on to step 6:
87 can be fit into 483 5 times, resulting in a remainder of 48.
Put 5 as the next digit of the answer. 
Result so far: 7685.0
If we subtract 435 from 483, we get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

On to step 7:
87 can be fit into 480 5 times, resulting in a remainder of 45.
Write down 5 as next digit of the result. 
Result so far: 7685.5
If we take 435 away from 480, we end up with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 8:
87 goes into 450 5 times with a remainder of 15.
The next digit of our result is 5. 
Result so far: 7685.55
Subtracting 435 from 450 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

After the division, we end up with 7685.55 and a remainder of 0.015.