Daftar Isi:A. Introduction 1. Background of the Study 2. Design of the Study B. Theoretical Background 1. Constructivism in Mathematics Education 2. Students Motivation in Mathematics 3. Students Performance in Mathematics 4. Teachers Mathematical Beliefs 5. Didactical Situation in Mathematics 6. Outdoor Mathematics Education 7. Technology in Mathematics Education 8. Conceptual Framework of the Study C The MathCityMap Project 1. The Concept and the Goals of the Project 2. Components of the Project a. Mathematical Outdoor Tasks b. Mathematical City Trips c. Map-Based Mobile App d. MathCityMap Community 3. Technical Implementation of the Project 4. Steps of Preparation 5. Settings of the Activity 6. Evaluating and Publishing the Activity D Designing the Mobile App-Supported Math Trail Environment in Indonesia 1. Indonesian Secondary School Mathematics Education a. A Brief Profile of Indonesia b. Education System in Indonesia c. Indonesian Secondary School Mathematics Curriculum 2. Design of the Mobile App-Supported Math Trail Programme for Indonesia a. Design of the Rules of the Activity b. Design of the Mobile App c. Design of the Math Trails E. Evaluating the Potential Effects of a Mobile App-Supported Math Trail Programme An Exploration Study in Indonesia 1. Method a. Approach b. Participants Situations Activities and Procedures c. Data Collection and Analysis 2. Results a. What Was the Initial Condition of the Students Like b. How Has the Programme Been Running c. How Did the Students Work d. Why Do Students Engage in This Programme e. What Mathematical Experience Do They Get After Having Engaged in This Programme f. Does the Intervention Promote Students Performance in Mathematics g. How Does the Project Affect Teachers Mathematical Beliefs 3. Discussion F. Conclusions and Recommendations 1. Conclusions a. The MathCityMap Project b. The Mobile App-Supported Math Trail Programme in Indonesia c. Implementation and Empirical Study of the Programme in Indonesia d. The Answer to the First Research Question The Students Motivation to Engage in Mathematics e. The Answer to the Second Research Question The Students Performance in Mathematics f. The Answer to the Third Research Question The Teachers Mathematical Beliefs g. Remarks from the Answers to the Three Research Questions i. Some Criticism of the MathCityMap Project 2. Recommendations