80490 ÷ 21 
We want to divide 80490 by 21.

Moving on to step 1:
21 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Grab the next digit (0) from the dividend, add it to 8, then carry on: 80 / 21

Going ahead to step 2:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtract 63 from 80 to get 17.
Grab the next digit (4) from the dividend, add it to 17, then carry on: 174 / 21

Let's proceed to step 3:
21 can be fit into 174 8 times, resulting in a remainder of 6.
The next digit of our result is 8. 
Result so far: 38.0
If we take 168 away from 174, we end up with 6.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 21

Step 4:
When dividing 69 by 21, we get 3 with a remainder of 6.
Write down 3 as next digit of the result. 
Result so far: 383.0
The remainder is 6 after subtracting 63 from 69.
Grab the next digit (0) from the dividend, add it to 6, then carry on: 60 / 21

Let's proceed to step 5:
If we divide 60 by 21, we get 2 and a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 3832.0
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 6:
180 divided by 21 is 8 with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 3832.8
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 7:
If we divide 120 by 21, we get 5 and a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 3832.85
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 8:
21 goes into 150 7 times with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 3832.857
If we subtract 147 from 150, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 9:
If we divide 30 by 21, we get 1 and a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 3832.8571
Subtracting 21 from 30 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 10:
21 goes into 90 4 times with a remainder of 6.
The next digit of our result is 4. 
Result so far: 3832.85714
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 11:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 3832.857142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 12:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 3832.8571428
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 13:
The number 21 fits into 120 5 times, leaving a remainder of 15.
The next digit of our result is 5. 
Result so far: 3832.85714285
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

After the division, we end up with 3832.85714285 and a remainder of 1.5e-08.