300421 divided by 80 
Our goal is to divide 300421 by 80.

Moving on to step 1:
If we divide 3 by 80, we get 0 and a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Bring next digit (0) of the dividend behind the 3 and repeat the process: 30 / 80

Advancing to step 2:
30 divided by 80 is 0 with a remainder of 30.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 30, we end up with 30.
Include the next digit (0) from the dividend after 30, then repeat: 300 / 80

Step 3:
300 divided by 80 is 3 with a remainder of 60.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Deduct 240 from 300 and we're left with 60.
Include the next digit (4) from the dividend after 60, then repeat: 604 / 80

Advancing to step 4:
80 goes into 604 7 times with a remainder of 44.
The number 7 becomes the next digit in our result. 
Result so far: 37.0
The remainder is 44 after subtracting 560 from 604.
Grab the next digit (2) from the dividend, add it to 44, then carry on: 442 / 80

Advancing to step 5:
When dividing 442 by 80, we get 5 with a remainder of 42.
Put 5 as the next digit of the answer. 
Result so far: 375.0
Deduct 400 from 442 and we're left with 42.
Grab the next digit (1) from the dividend, add it to 42, then carry on: 421 / 80

Let's proceed 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: 3755.0
Subtract 400 from 421 to get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 7:
If we divide 210 by 80, we get 2 and a remainder of 50.
Use 2 as the next digit of our solution. 
Result so far: 3755.2
If we take 160 away from 210, 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.

Advancing to step 8:
If we divide 500 by 80, we get 6 and a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 3755.26
The remainder is 20 after subtracting 480 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 9:
If we divide 200 by 80, we get 2 and a remainder of 40.
The number 2 becomes the next digit in our result. 
Result so far: 3755.262
The remainder is 40 after subtracting 160 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 10:
The number 80 fits into 400 5 times, leaving a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 3755.2625
Subtract 400 from 400 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.

Moving on to step 11:
80 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 3755.2625
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.

Advancing to step 12:
80 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 3755.2625
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.

Our division results in 3755.2625 with a remaining 0.0.