668690 ÷ 80 
Our goal is to divide 668690 by 80.

Step 1:
If we divide 6 by 80, we get 0 and a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 80

Let's proceed to step 2:
80 can be fit into 66 0 times, resulting in a remainder of 66.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 66 to get 66.
Grab the next digit (8) from the dividend, add it to 66, then carry on: 668 / 80

Going ahead to step 3:
When dividing 668 by 80, we get 8 with a remainder of 28.
Record the quotient 8 as the next digit in the result. 
Result so far: 8.0
If we subtract 640 from 668, we get 28.
Append the next digit (6) from the dividend to 28 and continue with: 286 / 80

On to step 4:
286 divided by 80 is 3 with a remainder of 46.
Use 3 as the next digit of our solution. 
Result so far: 83.0
The remainder is 46 after subtracting 240 from 286.
Include the next digit (9) from the dividend after 46, then repeat: 469 / 80

Let's proceed to step 5:
The number 80 fits into 469 5 times, leaving a remainder of 69.
Record the quotient 5 as the next digit in the result. 
Result so far: 835.0
Subtract 400 from 469 to get 69.
Fetch the next digit (0) from the dividend, attach it to 69 and continue: 690 / 80

Going ahead to step 6:
If we divide 690 by 80, we get 8 and a remainder of 50.
The number 8 becomes the next digit in our result. 
Result so far: 8358.0
The remainder is 50 after subtracting 640 from 690.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Going ahead to step 7:
80 can be fit into 500 6 times, resulting in a remainder of 20.
Write down 6 as next digit of the result. 
Result so far: 8358.6
If we subtract 480 from 500, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 8:
When dividing 200 by 80, we get 2 with a remainder of 40.
The next digit of our result is 2. 
Result so far: 8358.62
If we take 160 away from 200, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Advancing to step 9:
400 divided by 80 is 5 with a remainder of 0.
Use 5 as the next digit of our solution. 
Result so far: 8358.625
The remainder is 0 after subtracting 400 from 400.
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:
0 divided by 80 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 8358.625
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.

Advancing to step 11:
80 goes into 0 0 times with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 8358.625
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.

In conclusion, the division gives 8358.625 with a balance of 0.0.