We're dividing 428521 by 80 
We want to divide 428521 by 80.

Advancing to step 1:
80 can be fit into 4 0 times, resulting in a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 80

Step 2:
42 divided by 80 is 0 with a remainder of 42.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 42 after subtracting 0 from 42.
Fetch the next digit (8) from the dividend, attach it to 42 and continue: 428 / 80

Let's proceed to step 3:
80 can be fit into 428 5 times, resulting in a remainder of 28.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
If we take 400 away from 428, we end up with 28.
Include the next digit (5) from the dividend after 28, then repeat: 285 / 80

Step 4:
80 can be fit into 285 3 times, resulting in a remainder of 45.
Use 3 as the next digit of our solution. 
Result so far: 53.0
Subtracting 240 from 285 leaves us with 45.
Bring next digit (2) of the dividend behind the 45 and repeat the process: 452 / 80

Step 5:
If we divide 452 by 80, we get 5 and a remainder of 52.
Use 5 as the next digit of our solution. 
Result so far: 535.0
The remainder is 52 after subtracting 400 from 452.
Include the next digit (1) from the dividend after 52, then repeat: 521 / 80

Moving on to step 6:
When dividing 521 by 80, we get 6 with a remainder of 41.
Write down 6 as next digit of the result. 
Result so far: 5356.0
If we take 480 away from 521, we end up with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Going ahead to step 7:
When dividing 410 by 80, we get 5 with a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 5356.5
Subtracting 400 from 410 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 8:
80 can be fit into 100 1 times, resulting in a remainder of 20.
The number 1 becomes the next digit in our result. 
Result so far: 5356.51
If we subtract 80 from 100, 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.

Moving on to step 9:
The number 80 fits into 200 2 times, leaving a remainder of 40.
Write down 2 as next digit of the result. 
Result so far: 5356.512
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.

Step 10:
When dividing 400 by 80, we get 5 with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 5356.5125
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.

Moving on to step 11:
When dividing 0 by 80, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 5356.5125
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.

Moving on to step 12:
When dividing 0 by 80, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 5356.5125
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.

After the division, we end up with 5356.5125 and a remainder of 0.0.