We're dividing 821021 by 10 
We want to figure out the number of times 821021 can be divided by 10.

On to step 1:
When dividing 8 by 10, we get 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Include the next digit (2) from the dividend after 8, then repeat: 82 / 10

Moving on to step 2:
10 can be fit into 82 8 times, resulting in a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
If we take 80 away from 82, we end up with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 10

On to step 3:
21 divided by 10 is 2 with a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 82.0
The remainder is 1 after subtracting 20 from 21.
Take the next digit (0) from the dividend and append it to 1, then repeat: 10 / 10

Step 4:
10 can be fit into 10 1 times, resulting in a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 821.0
If we take 10 away from 10, we end up with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 10

Step 5:
When dividing 2 by 10, we get 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 8210.0
Subtract 0 from 2 to get 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 10

Moving on to step 6:
21 divided by 10 is 2 with a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 82102.0
Deduct 20 from 21 and we're left 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.

Going ahead to step 7:
10 divided by 10 is 1 with a remainder of 0.
Record the quotient 1 as the next digit in the result. 
Result so far: 82102.1
Subtract 10 from 10 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.

On to step 8:
0 divided by 10 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 82102.1
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.

Moving on to step 9:
The number 10 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 82102.1
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.

The final result is 82102.1 with a remainder of 0.0.