3.1. Unit Overview¶
This unit extends the student’s mobile programming toolkit to several new App Inventor components and introduces a number of new programming concepts, including the concepts of variables, lists and data abstraction. The main app in this unit, The Paint Pot app, a computational model of finger painting, focuses on App Inventor's drawing and painting features and related topics from the CS Principles framework. The app is presented in three parts each of which is followed by a set of creative project exercises and challenges. This unit also introduces two other apps: Map Tour app, which provides a first introduction to lists, and Map Tour with TinyDB, which demonstrates how to incorporate external data and location into a mobile app. Unit 3 also extends the student’s understanding of the binary number system and introduces students to the idea of a bit as the fundamental unit of data. Through a number of hands-on and interactive activities, students explore how bits are used to represent images, and how redundant parity bits can be used to detect simple data transmission errors. These lessons are complemented by an Impact of CS reading and activity.