ABSTRACT
Mathematics is about much more than knowing facts. However, some facts are useful as they support us in carrying out calculations quickly and in being able to check that our answers to problems are accurate. During 2019 and 2020 the discussion around Cognitive Load Theory (CLT) grew. The impact of the interpretations of the theory became visible in classrooms and is discussed both across social media and at academic conferences. CLT is a theory from cognitive psychology rather than education and refers to the amount of ‘working memory’ that an individual uses, when thinking about a topic or trying to solve a problem. The chapter shows the development of children’s knowledge of number facts as learners move through primary school. It also shows practising teachers what they might expect the learners in their class to have experienced before they meet practising teachers.
