309870 divided by 81 
Our goal is to divide 309870 by 81.

Step 1:
81 can be fit into 3 0 times, resulting in a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 81

On to step 2:
When dividing 30 by 81, we get 0 with a remainder of 30.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 30 leaves us with 30.
Bring next digit (9) of the dividend behind the 30 and repeat the process: 309 / 81

Moving on to step 3:
The number 81 fits into 309 3 times, leaving a remainder of 66.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 243 from 309 and we're left with 66.
Include the next digit (8) from the dividend after 66, then repeat: 668 / 81

On to step 4:
The number 81 fits into 668 8 times, leaving a remainder of 20.
Use 8 as the next digit of our solution. 
Result so far: 38.0
If we take 648 away from 668, we end up with 20.
Fetch the next digit (7) from the dividend, attach it to 20 and continue: 207 / 81

On to step 5:
81 can be fit into 207 2 times, resulting in a remainder of 45.
The next digit of our result is 2. 
Result so far: 382.0
If we subtract 162 from 207, we get 45.
Fetch the next digit (0) from the dividend, attach it to 45 and continue: 450 / 81

On to step 6:
The number 81 fits into 450 5 times, leaving a remainder of 45.
Record the quotient 5 as the next digit in the result. 
Result so far: 3825.0
If we take 405 away from 450, we end up with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

On to step 7:
The number 81 fits into 450 5 times, leaving a remainder of 45.
Use 5 as the next digit of our solution. 
Result so far: 3825.5
Deduct 405 from 450 and we're left with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Moving on to step 8:
The number 81 fits into 450 5 times, leaving a remainder of 45.
Record the quotient 5 as the next digit in the result. 
Result so far: 3825.55
Subtract 405 from 450 to get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

The final outcome is 3825.55, with a leftover of 0.045.