We divide 80300971 by 21
Our goal is to divide 80300971 by 21.

On to step 1:
8 divided by 21 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 21

Advancing to step 2:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 63 from 80 and we're left with 17.
Grab the next digit (3) from the dividend, add it to 17, then carry on: 173 / 21

Advancing to step 3:
If we divide 173 by 21, we get 8 and a remainder of 5.
Record the quotient 8 as the next digit in the result. 
Result so far: 38.0
If we subtract 168 from 173, we get 5.
Append the next digit (0) from the dividend to 5 and continue with: 50 / 21

Step 4:
50 divided by 21 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 382.0
The remainder is 8 after subtracting 42 from 50.
Grab the next digit (0) from the dividend, add it to 8, then carry on: 80 / 21

Advancing to step 5:
When dividing 80 by 21, we get 3 with a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 3823.0
If we subtract 63 from 80, we get 17.
Fetch the next digit (9) from the dividend, attach it to 17 and continue: 179 / 21

Let's proceed to step 6:
The number 21 fits into 179 8 times, leaving a remainder of 11.
Write down 8 as next digit of the result. 
Result so far: 38238.0
If we take 168 away from 179, we end up with 11.
Fetch the next digit (7) from the dividend, attach it to 11 and continue: 117 / 21

On to step 7:
If we divide 117 by 21, we get 5 and a remainder of 12.
Record the quotient 5 as the next digit in the result. 
Result so far: 382385.0
The remainder is 12 after subtracting 105 from 117.
Fetch the next digit (1) from the dividend, attach it to 12 and continue: 121 / 21

Going ahead to step 8:
21 can be fit into 121 5 times, resulting in a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 3823855.0
The remainder is 16 after subtracting 105 from 121.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 9:
21 goes into 160 7 times with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 3823855.7
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 10:
When dividing 130 by 21, we get 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 3823855.76
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 11:
When dividing 40 by 21, we get 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 3823855.761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 12:
21 goes into 190 9 times with a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 3823855.7619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 13:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 3823855.7619
If we subtract 0 from 10, we get 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 14:
21 goes into 100 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 3823855.761904
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 15:
21 goes into 160 7 times with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 3823855.7619047
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 16:
21 goes into 130 6 times with a remainder of 4.
The next digit of our result is 6. 
Result so far: 3823855.76190476
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final result is 3823855.76190476 with a remainder of 4e-09.