Computational thinking is considered a necessary skill in the 21st century. However, few teacher-education programs offer training for pre-service teachers to learn how to integrate computational thinking into the classroom. Pre-service teachers need to gain the knowledge and experience of computational thinking so that they are confident about designing relevant instructions in the future. The purpose of this chapter is to show how a free elective course in the teacher education program provides learning opportunities for them to develop their computational thinking skills and knowledge through the use of tangible objects. Samples of their works were analysed at different stages of learning to illustrate the technological pedagogical content knowledge of computational thinking. Overall, the study demonstrates that pre-service teachers were able to develop knowledge and attitudes towards computational thinking with their experience in the teacher education course.