We divide 640258 by 3
Let's see how many times 3 fits into 640258.

Moving on to step 1:
3 can be fit into 6 2 times, resulting in a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we subtract 6 from 6, we get 0.
Include the next digit (4) from the dividend after 0, then repeat: 4 / 3

Step 2:
When dividing 4 by 3, we get 1 with a remainder of 1.
Record the quotient 1 as the next digit in the result. 
Result so far: 21.0
The remainder is 1 after subtracting 3 from 4.
Take the next digit (0) from the dividend and append it to 1, then repeat: 10 / 3

Let's proceed to step 3:
If we divide 10 by 3, we get 3 and a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 213.0
Deduct 9 from 10 and we're left with 1.
Grab the next digit (2) from the dividend, add it to 1, then carry on: 12 / 3

Moving on to step 4:
3 goes into 12 4 times with a remainder of 0.
Write down 4 as next digit of the result. 
Result so far: 2134.0
Subtracting 12 from 12 leaves us with 0.
Fetch the next digit (5) from the dividend, attach it to 0 and continue: 5 / 3

Step 5:
3 can be fit into 5 1 times, resulting in a remainder of 2.
The number 1 becomes the next digit in our result. 
Result so far: 21341.0
Deduct 3 from 5 and we're left with 2.
Fetch the next digit (8) from the dividend, attach it to 2 and continue: 28 / 3

Advancing to step 6:
3 can be fit into 28 9 times, resulting in a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 213419.0
If we subtract 27 from 28, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 7:
10 divided by 3 is 3 with a remainder of 1.
Record the quotient 3 as the next digit in the result. 
Result so far: 213419.3
If we take 9 away from 10, we end up 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.

Moving on to step 8:
3 goes into 10 3 times with a remainder of 1.
The next digit of our result is 3. 
Result so far: 213419.33
If we take 9 away from 10, we end up 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.

The final result is 213419.33 with a remainder of 0.001.