1. Overcoming visual obstacles with the aid of the Supposer

   • Michal Yerushalmy
   • Daniel Chazan

   OriginalPaper Pages: 199 - 219

2. Scores and foreits — An intuitive model for integer arithmetic

   • Pamela Liebeck

   OriginalPaper Pages: 221 - 239

3. Solution strategies: Subtraction number facts

   • Carol A. Thornton

   OriginalPaper Pages: 241 - 263

4. Preservice education of math teachers using paradoxes

   • Nitsa Movshovitz-Hadar
   • Rina Hadass

   OriginalPaper Pages: 265 - 287

5. Doing critical cultural and ideological technology

   • Gordon Burt

   Short Communication Pages: 289 - 298