Stage: Challenge Level: 
Generalising. Tangram. Practical Activity. Cubes. Interactivities. Compound transformations. Visualising. Addition & subtraction. Games. Working systematically.
Published October 2001.
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