Technology is playing an increasingly important role in the teaching and learning of mathematics at all levels. This publication reports on overviews of research and findings on the impact of technology. It furnishes a context in which to observe teachers in prekindergarten through grade 12 and teacher educators using technology to help their students better understand mathematics, and suggests what the future might hold. An accompanying CD includes electronic features to enhance an understanding of the articles presented in the printed yearbook. Following Preface and Prologue, Twenty-three chapters are presented in three parts. Part 1, How Research Informs, includes: (1) Teaching Strategies for Developing Judicious Technology Use (Lynda Ball and Kaye Stacey); (2) Young Children's Use of Virtual Manipulatives and Other Forms of Mathematical Representations (Patricia S. Moyer, Deborah Niezgoda, and John Stanley); (3) Five Steps to Zero: Students Developing Elementary Number Theory Concepts When Using Calculators (Carolyn Kieran and Jose Guzman); (4) Young Children and Technology: What's Appropriate? (Douglas H. Clements and Julie Sarama); (5) Comparing Distributions and Growing Samples by Hand and with a Computer Tool (Arthur Bakker and Ann Frederickson); (6) Interactive Geometry Software and Mechanical Linkages: Scaffolding Students' Deductive Reasoning (Jill Vincent); (7) Square or Not? Assessing Constructions in an Interactive Geometry Software (Daniel Scher); and (8) An Anthropological Account of the Emergence of Mathematical Proof and Related Processes in Technology-Based Environments (F. D. Rivera). Part 2, Notes from the Field, includes: (9) The Reality of Using Technology in the Classroom (Suzanne Alejandre); (10) Using Technology to Foster Students' Mathematical Understandings and Intuitions (Eric J. Knuth and Christopher E. Hartmann); (11) The Spreadsheet: A Vehicle for Connecting Proportional Reasoning to the Real World in a Middle School Classroom (Richard Caulfield, Paul E. Smith, and Kelly McCormick); (12) Using Spreadsheet Software to Explore Measures of Central Tendency and Variability (Carol S. Parke); (13) Internet WebQuest: A Context for Mathematics Process Skills (Leah P. McCoy); (14) A Vehicle for Mathematics Lessons: In-Service Teachers Learning to Use PDAs in Their Classroom (Julie Cwikla); (15) Using the Internet to Illuminate NCTM's "Principles and Standards for School Mathematics" (Eric W. Hart, Sabrina Keller, W. Gary Martin, Carol Midgett, and S. Thomas Gorski); (16) Mathematics Teaching and Learning Supported by the Internet (Enrique Galindo); (17) Laptops in the Middle School Mathematics Classroom (Suzanne Lewis); (18) The Role of Technology in Representing Mathematical Problem Situations and Concepts (Dominic D. Peressini and Eric J. Knuth); (19) Using Technology to Make the Power of Many Points with Prospective Mathematics Teachers (Rose Mary Zbiek); (20) Investigating Mathematics with Technology: Lesson Structures That Encourage a Range of Methods and Solutions (Rebecca McGraw and Maureen Grant); (21) Engaging Students in Authentic Mathematics Activities through Calculators and Small Robots (George C. Reese, Jennifer Dick, James P. Dildine, Kathleen Smith, Mikkel Storaasli, Kenneth J. Travers, Susan Wotal, and Dalia Zygas); and (22) Using GIS to Transform the Mathematical Landscape (Bob Coulter and Joseph J. Kerski). Part 3, Questions about the Future, includes: (23) Technology in Mathematics Education: Tapping into Visions of the Future (M. Kathleen Heid). [For the 66th Yearbook, see ED495227.]