We look at the division of 80496730 by 21 
We're looking to find how many times 21 goes into 80496730.

Step 1:
The number 21 fits into 8 0 times, leaving a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 21

Step 2:
21 goes into 80 3 times with a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Deduct 63 from 80 and we're left with 17.
Take the next digit (4) from the dividend and append it to 17, then repeat: 174 / 21

On to step 3:
21 goes into 174 8 times with a remainder of 6.
The next digit of our result is 8. 
Result so far: 38.0
Subtracting 168 from 174 leaves us with 6.
Take the next digit (9) from the dividend and append it to 6, then repeat: 69 / 21

Going ahead to step 4:
The number 21 fits into 69 3 times, leaving a remainder of 6.
The number 3 becomes the next digit in our result. 
Result so far: 383.0
If we take 63 away from 69, we end up with 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 21

Going ahead to step 5:
66 divided by 21 is 3 with a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 3833.0
If we take 63 away from 66, we end up with 3.
Append the next digit (7) from the dividend to 3 and continue with: 37 / 21

Step 6:
21 goes into 37 1 times with a remainder of 16.
Use 1 as the next digit of our solution. 
Result so far: 38331.0
Subtracting 21 from 37 leaves us with 16.
Bring next digit (3) of the dividend behind the 16 and repeat the process: 163 / 21

Advancing to step 7:
If we divide 163 by 21, we get 7 and a remainder of 16.
The next digit of our result is 7. 
Result so far: 383317.0
Deduct 147 from 163 and we're left with 16.
Grab the next digit (0) from the dividend, add it to 16, then carry on: 160 / 21

Step 8:
21 goes into 160 7 times with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 3833177.0
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 9:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 3833177.6
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.

Going ahead to step 10:
If we divide 40 by 21, we get 1 and a remainder of 19.
The next digit of our result is 1. 
Result so far: 3833177.61
If we subtract 21 from 40, we get 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 11:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 3833177.619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 12:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 3833177.619
Deduct 0 from 10 and we're left 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.

Moving on to step 13:
When dividing 100 by 21, we get 4 with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 3833177.61904
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.

Advancing to step 14:
21 can be fit into 160 7 times, resulting in a remainder of 13.
The next digit of our result is 7. 
Result so far: 3833177.619047
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.

Going ahead to step 15:
130 divided by 21 is 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 3833177.6190476
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.

Let's proceed to step 16:
40 divided by 21 is 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 3833177.61904761
Deduct 21 from 40 and we're left 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.

After the division, we end up with 3833177.61904761 and a remainder of 1.9e-08.