509865 ÷ 3 
Let's see how many times 3 fits into 509865.

On to step 1:
The number 3 fits into 5 1 times, leaving a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 3 from 5 leaves us with 2.
Include the next digit (0) from the dividend after 2, then repeat: 20 / 3

Step 2:
3 goes into 20 6 times with a remainder of 2.
The next digit of our result is 6. 
Result so far: 16.0
If we take 18 away from 20, we end up with 2.
Take the next digit (9) from the dividend and append it to 2, then repeat: 29 / 3

Moving on to step 3:
The number 3 fits into 29 9 times, leaving a remainder of 2.
The next digit of our result is 9. 
Result so far: 169.0
Deduct 27 from 29 and we're left with 2.
Fetch the next digit (8) from the dividend, attach it to 2 and continue: 28 / 3

Moving on to step 4:
The number 3 fits into 28 9 times, leaving a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 1699.0
The remainder is 1 after subtracting 27 from 28.
Grab the next digit (6) from the dividend, add it to 1, then carry on: 16 / 3

Let's proceed to step 5:
3 goes into 16 5 times with a remainder of 1.
Write down 5 as next digit of the result. 
Result so far: 16995.0
Subtract 15 from 16 to get 1.
Take the next digit (5) from the dividend and append it to 1, then repeat: 15 / 3

On to step 6:
The number 3 fits into 15 5 times, leaving a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 169955.0
Subtract 15 from 15 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.

Advancing to step 7:
When dividing 0 by 3, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 169955.0
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.

Let's proceed to step 8:
3 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 169955.0
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.

The quotient of the division is 169955.0, and the remainder is 0.0.