Start with 27 small cubes. Now put them together to make one larger cube. Without touching the sides of the larger cube, remove the cube in the middle to leave 26.
(Note: No one may touch the outer cubes or in any way do anything that would move or change them)
(In reply to
Hints: by Gamer)
Gamer, if your comment was directed at me, and the answer is... the middle cube is ice... well... I didn't "give it away"... Nikki already suggested that in the second comment.
But, more than that, I am still a student. I don't have access to the queue, so I couldn't possibly have seen the answer. (Even if I did, I wouldn't dream of revealing the solution if I had prior access to it.)