The Poly-Universe methodology book is available now in an online version with several hundred exercises for school children between the age 6 and 18 .
Download the complete book or chosen exercises according to your preference: http://poly-universe.com/puse-treasury/ (you have to login first).
Age recommendation: 3+
The inventor of the unique geometrical system is Hungarian visual artist János Saxon-Szász. The tool is produced by Poly-Universe Ltd in Hungary.