512858 ÷ 3 
We want to figure out the number of times 512858 can be divided by 3.

Moving on to step 1:
3 can be fit into 5 1 times, resulting in a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 2 after subtracting 3 from 5.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 3

Advancing to step 2:
3 can be fit into 21 7 times, resulting in a remainder of 0.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
The remainder is 0 after subtracting 21 from 21.
Grab the next digit (2) from the dividend, add it to 0, then carry on: 2 / 3

Going ahead to step 3:
2 divided by 3 is 0 with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 170.0
Deduct 0 from 2 and we're left with 2.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 3

On to step 4:
28 divided by 3 is 9 with a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 1709.0
Subtract 27 from 28 to get 1.
Include the next digit (5) from the dividend after 1, then repeat: 15 / 3

On to step 5:
3 can be fit into 15 5 times, resulting in a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 17095.0
Deduct 15 from 15 and we're left with 0.
Append the next digit (8) from the dividend to 0 and continue with: 8 / 3

Step 6:
8 divided by 3 is 2 with a remainder of 2.
Put 2 as the next digit of the answer. 
Result so far: 170952.0
Subtract 6 from 8 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 7:
The number 3 fits into 20 6 times, leaving a remainder of 2.
Write down 6 as next digit of the result. 
Result so far: 170952.6
If we take 18 away from 20, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 8:
If we divide 20 by 3, we get 6 and a remainder of 2.
Use 6 as the next digit of our solution. 
Result so far: 170952.66
If we subtract 18 from 20, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Our division results in 170952.66 with a remaining 0.002.