639917 ÷ 80 
Let's see how many times 80 fits into 639917.

Let's proceed to step 1:
If we divide 6 by 80, we get 0 and 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.
Take the next digit (3) from the dividend and append it to 6, then repeat: 63 / 80

Going ahead to step 2:
80 goes into 63 0 times with a remainder of 63.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 63 to get 63.
Append the next digit (9) from the dividend to 63 and continue with: 639 / 80

Advancing to step 3:
The number 80 fits into 639 7 times, leaving a remainder of 79.
The next digit of our result is 7. 
Result so far: 7.0
If we subtract 560 from 639, we get 79.
Fetch the next digit (9) from the dividend, attach it to 79 and continue: 799 / 80

Advancing to step 4:
If we divide 799 by 80, we get 9 and a remainder of 79.
Put 9 as the next digit of the answer. 
Result so far: 79.0
If we subtract 720 from 799, we get 79.
Grab the next digit (1) from the dividend, add it to 79, then carry on: 791 / 80

Going ahead to step 5:
If we divide 791 by 80, we get 9 and a remainder of 71.
The number 9 becomes the next digit in our result. 
Result so far: 799.0
Subtract 720 from 791 to get 71.
Include the next digit (7) from the dividend after 71, then repeat: 717 / 80

Step 6:
The number 80 fits into 717 8 times, leaving a remainder of 77.
Use 8 as the next digit of our solution. 
Result so far: 7998.0
Deduct 640 from 717 and we're left with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

Advancing to step 7:
The number 80 fits into 770 9 times, leaving a remainder of 50.
The next digit of our result is 9. 
Result so far: 7998.9
If we take 720 away from 770, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

On to step 8:
The number 80 fits into 500 6 times, leaving a remainder of 20.
Write down 6 as next digit of the result. 
Result so far: 7998.96
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.

On to step 9:
If we divide 200 by 80, we get 2 and a remainder of 40.
Use 2 as the next digit of our solution. 
Result so far: 7998.962
Subtracting 160 from 200 leaves us 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.

On to step 10:
When dividing 400 by 80, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 7998.9625
Deduct 400 from 400 and we're left 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 11:
The number 80 fits into 0 0 times, leaving a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 7998.9625
Deduct 0 from 0 and we're left 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 12:
0 divided by 80 is 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 7998.9625
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.

In conclusion, the division gives 7998.9625 with a balance of 0.0.