This document contains Volumes 1 and 2 of the proceedings of the 23rd annual conference of the Mathematics Education Research Group of Australasia Incorporated (MERGA) held at Fremantle, Western Australia, July 5-9, 2000. Papers in Volume 1 include: (1) "Bridging Practices: Intertwining Content and Pedagogy in Teaching and Learning To Teach" (Deborah Loewenberg Ball); (2) "Looking Backwards, Looking Forwards, and Looking for Direction" (Andy Begg); (3) "Bridging the Gap: A Challenge for the Dual Community" (John A. Malone); (4) "Collaborative Problem Solving in Senior Secondary Mathematics Classrooms" (Merrilyn Goos); (5) "Changing the Professional Knowledge of Teachers" (Janette Bobis and Peter Gould); (6) "Teachers, Students and Research: One Possibility for Teaching Early Numeracy" (Philip Clarkson); (7) "Mapping Children's Stages of Arithmetical Solution Methods" (Peter Gould and Robert Wright); (8) "Reviewing Literature Relevant to a Systemic Early Numeracy Initiative: Bases of CMIT" (Robert Wright and Peter Gould); (9) "Emergence of Mathematical (In)Competence and Identity" (Pat Forster and Peter Taylor); (10) "Is There More to Numeracy Than Meets the Eye? Stories of Socialization and Subjectification in School Mathematics" (Mary Klein); (11) "Mental Effort and Errors in Bracket Expansion Tasks" (Paul Ayres); (12) "Developing Task Specific Criteria: A Preliminary Report" (Dawn Bartlett); (13) "Construction of a Numeration Model: A Theoretical Analysis" (Annette Baturo); (14) "Modes of Representation in Students' Explanations" (Brenda Bicknell); and (15)"What Is Taught versus What Is Learnt: The Case of Linear Measurement" (Philippa Bragg and Lynne Outhred). Papers in Volume 2 include: (1) "Classroom and Teacher Effects in Mathematics Achievement: Results from TIMSS" (Stephen Lamb and Sue Fullarton); (2) "3-Dimensional Geometry: Assessment of Students' Responses" (Chrisitine Lawrie and John Pegg); (3) "Mathematics and Gender: Beliefs They Are a-Changin'" (Gilah Leder and Helen Forgasz); (4) "Informal Assessment Questions Used by Secondary School Mathematics Teachers" (Sanka Liyanage, Kathryn Irwin, and Mike Thomas); (5) "Grade 1 Children in Problem-Posing Contexts: Problem Solving Prior to Completing the Task" (Tom Lowrie); (6) "Knowledge and Strategies Students Employ To Solve Open-Ended Problem-Solving Activities" (Tom Lowrie, Rod Francis, and Geoff Rogers); (7) "Mental Computation, Number Sense and General Mathematics Ability: Are They Linked?" (Alistair McIntosh and Shelley Dole); (8) "Designing Constructivist Computer Games for Teaching about Decimal Numbers" (Janine McIntosh, Kaye Stacey, Calvin Tromp, and Darren Lightfoot); (9) "Scaffolding: A Suitable Teaching Characteristic in One-to-One Teaching in Maths Recovery" (Bronwyn McMahon); (10) "Low Achieving Mathematics Students' Attitudinal and Achievement Changes as a Result of Using an Integrated Learning System" (Campbell McRobbie, Annette Baturo, and Tom Cooper); (11) "Teaching for Abstraction: Reconstructing Constructivism" (Michael Mitchelmore and Paul White); (12) "Graphical Representations of Statistical Associations by Upper Primary Students" (Jonathan Moritz); (13) "Reasoning and Expressing Probability in Students' Judgements of Coin Tossing" (Jonathan Moritz and Jane Watson); (14) "The Practicum as Context: Two Snapshots" (Judith Mousley and Georgina Herbert); and (15) "A Comparative Analysis of the 1996-1999 Calculus TEE Papers" (Ute Mueller and Patricia Forster). (ASK)