Summer Edition 2004 © 2004 TABLE OF CONTENTS

K-8 Teacher Candidates' Use of Mathematical Representations and the Development of Their Pedagogical Content Knowledge as Exhibited in Their Lesson Planning Robin A. Ward, Cynthia O. Anhalt, and Kevin D. Vinson

Pre-service elementary teachers' Understanding of Geometric Similarity: The Effect of Dynamic Geometry Software Helen Gerretson

Repeating Pattern or Number pattern: The Distinction is Blurred Peter Liljedahl

Inaccurate Mental Addition and Subtraction: Causes and Compensation Ann M. Heirsfield and Tom J. Cooper