Computational Thinking has been described as an essential skill which everybody should learn. Since Wing popularised the term in 2006 increased focus and attention have been placed on Computational Thinking. The first aim of this systematic literary review is to give second-level educators, who are considering incorporating Computational Thinking into their classrooms, ideas and options about how to achieve this. The hope is also to present reasons as to why it is beneficial to teach Computational Thinking, along with potential issues. Secondly, we aim to present education researchers with an overview of what work has been carried out in the domain, as well as potential gaps that still exist. Thirdly, this is the first stage in a longer-term project to develop a Computational Thinking based curriculum which is taught using Computer Science. It is hoped that the problems and ideas that are presented here will underpin this curriculum.