Is 256 divisible by 2,3,5,9, and 10?
The short answer is no.
256 is divisible by 2 because 2 can go into it evenly.
256 is not divisible by three because if you divide it out, it doesn't come out evenly.
256 is not divisible by 5 because it doesn't end in 5 or 0.
256 is not divisible by 9 because again, if you divide it out, it doesn't come out evenly.
And lastly, 256 is not divisible by 10 because it does not end in zero.
A short cut I used to use on these problems is simply dividing the number (256) by the number you need to know is divisible (2,3,5,9, and 10).
Hope this helped :)