We're dividing 810594 by 21 
Our goal is to divide 810594 by 21.

Advancing to step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Take the next digit (1) from the dividend and append it to 8, then repeat: 81 / 21

Advancing to step 2:
21 goes into 81 3 times with a remainder of 18.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtract 63 from 81 to get 18.
Grab the next digit (0) from the dividend, add it to 18, then carry on: 180 / 21

On to step 3:
180 divided by 21 is 8 with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 38.0
Subtracting 168 from 180 leaves us with 12.
Fetch the next digit (5) from the dividend, attach it to 12 and continue: 125 / 21

Advancing to step 4:
21 can be fit into 125 5 times, resulting in a remainder of 20.
Use 5 as the next digit of our solution. 
Result so far: 385.0
Subtract 105 from 125 to get 20.
Include the next digit (9) from the dividend after 20, then repeat: 209 / 21

Going ahead to step 5:
When dividing 209 by 21, we get 9 with a remainder of 20.
Use 9 as the next digit of our solution. 
Result so far: 3859.0
Subtract 189 from 209 to get 20.
Bring next digit (4) of the dividend behind the 20 and repeat the process: 204 / 21

Step 6:
When dividing 204 by 21, we get 9 with a remainder of 15.
Use 9 as the next digit of our solution. 
Result so far: 38599.0
Subtract 189 from 204 to get 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 7:
21 goes into 150 7 times with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 38599.7
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 8:
21 goes into 30 1 times with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 38599.71
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.

Moving on to step 9:
When dividing 90 by 21, we get 4 with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 38599.714
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 10:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 38599.7142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 11:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 38599.71428
Deduct 168 from 180 and we're left 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.

Step 12:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 38599.714285
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.

Step 13:
If we divide 150 by 21, we get 7 and a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 38599.7142857
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.

On to step 14:
30 divided by 21 is 1 with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 38599.71428571
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.

After the division, we end up with 38599.71428571 and a remainder of 9e-09.