399621 divided by 80 
We're looking to find how many times 80 goes into 399621.

Going ahead to step 1:
When dividing 3 by 80, we get 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 80

Moving on to step 2:
When dividing 39 by 80, we get 0 with a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 39 to get 39.
Grab the next digit (9) from the dividend, add it to 39, then carry on: 399 / 80

Let's proceed to step 3:
399 divided by 80 is 4 with a remainder of 79.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we subtract 320 from 399, we get 79.
Fetch the next digit (6) from the dividend, attach it to 79 and continue: 796 / 80

Let's proceed to step 4:
When dividing 796 by 80, we get 9 with a remainder of 76.
Write down 9 as next digit of the result. 
Result so far: 49.0
The remainder is 76 after subtracting 720 from 796.
Append the next digit (2) from the dividend to 76 and continue with: 762 / 80

Advancing to step 5:
80 can be fit into 762 9 times, resulting in a remainder of 42.
Record the quotient 9 as the next digit in the result. 
Result so far: 499.0
Deduct 720 from 762 and we're left with 42.
Include the next digit (1) from the dividend after 42, then repeat: 421 / 80

Going ahead to step 6:
The number 80 fits into 421 5 times, leaving a remainder of 21.
Put 5 as the next digit of the answer. 
Result so far: 4995.0
If we take 400 away from 421, we end up with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Step 7:
When dividing 210 by 80, we get 2 with a remainder of 50.
Record the quotient 2 as the next digit in the result. 
Result so far: 4995.2
Subtract 160 from 210 to get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Step 8:
The number 80 fits into 500 6 times, leaving a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 4995.26
Subtract 480 from 500 to 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 9:
80 goes into 200 2 times with a remainder of 40.
The number 2 becomes the next digit in our result. 
Result so far: 4995.262
Deduct 160 from 200 and we're left 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 10:
If we divide 400 by 80, we get 5 and a remainder of 0.
The next digit of our result is 5. 
Result so far: 4995.2625
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:
80 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 4995.2625
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.

Going ahead to step 12:
If we divide 0 by 80, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 4995.2625
If we subtract 0 from 0, we 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.

Our division results in 4995.2625 with a remaining 0.0.