810330 divided by 21 
We're looking to find how many times 21 goes into 810330.

Step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 21

Going ahead to step 2:
If we divide 81 by 21, we get 3 and a remainder of 18.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtracting 63 from 81 leaves us with 18.
Grab the next digit (0) from the dividend, add it to 18, then carry on: 180 / 21

Advancing to step 3:
21 can be fit into 180 8 times, resulting in a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 38.0
Deduct 168 from 180 and we're left with 12.
Append the next digit (3) from the dividend to 12 and continue with: 123 / 21

Going ahead to step 4:
123 divided by 21 is 5 with a remainder of 18.
Use 5 as the next digit of our solution. 
Result so far: 385.0
The remainder is 18 after subtracting 105 from 123.
Include the next digit (3) from the dividend after 18, then repeat: 183 / 21

Advancing to step 5:
21 can be fit into 183 8 times, resulting in a remainder of 15.
The number 8 becomes the next digit in our result. 
Result so far: 3858.0
Deduct 168 from 183 and we're left with 15.
Fetch the next digit (0) from the dividend, attach it to 15 and continue: 150 / 21

Going ahead to step 6:
If we divide 150 by 21, we get 7 and a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 38587.0
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.

Moving on to step 7:
When dividing 30 by 21, we get 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 38587.1
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.

Let's proceed to step 8:
If we divide 90 by 21, we get 4 and a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 38587.14
Deduct 84 from 90 and we're left 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.

Moving on to step 9:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The next digit of our result is 2. 
Result so far: 38587.142
Subtract 42 from 60 to 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.

Step 10:
If we divide 180 by 21, we get 8 and a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 38587.1428
Subtract 168 from 180 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 11:
If we divide 120 by 21, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 38587.14285
Deduct 105 from 120 and we're left 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.

Moving on to step 12:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 38587.142857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 13:
When dividing 30 by 21, we get 1 with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 38587.1428571
Deduct 21 from 30 and we're left 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.

Let's proceed to step 14:
21 goes into 90 4 times with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 38587.14285714
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The final result is 38587.14285714 with a remainder of 6e-09.