Stage: 3 Challenge Level: 
This is quite a difficult problem to imagine in your head. If you've tried very hard without success, then actually dangle a cube into some water.
Squares. Visualising. Shape, space & measures - generally. Mathematical reasoning & proof. Working systematically. Interactivities. Games. smartphone. Generalising. Cubes.
Published February 2003.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk