Learning composite and prime numbers through developing an app: An example of computational thinking development through primary mathematics learning

Computational Thinking (CT) is a universal competence that young learners should acquire. This study illustrates the development of CT through app development for the learning of composite and prime numbers in primary school mathematics. Learners begin with inquiry activities regarding the meaning of composite numbers and prime numbers, and they are guided to find the factors of a given number by exploring an algorithm that involves the concept of modulo and can be implemented in a programming environment. Learners use a simple app to learn how the operator MOD works and then work in pairs to design an algorithm and devise a programming solution to find the factors of a given number by reusing the code of the simple app. The app will tell the users whether an inputted number is a composite or prime. Learners will make an initial connection with cryptography when large numbers such as 563,879 are explored, and they will obtain a more in-depth understanding of composite and prime numbers when 1 and 0 are tested in the app. In the process of building the app, learners will learn CT concepts such as sequence, loops, conditionals, events, operators and procedures. Learners will experience CT practices like reusing and remixing, being iterative and incremental, testing and debugging, abstracting and modularising and algorithmic thinking in developing the app. Learners will develop CT perspectives in the process of expressing, questioning and connecting with the digital world in developing the app. Copyright © 2019 The Author(s).