This book builds on the foundation laid in our earlier books Subitizing — Laying the foundations for number sense and Conceptual Subitizing — Laying the foundations for mental computation.
Subitizing and number strategies are now further developed to include rainbow facts, near doubles and near-rainbow facts. Use of the Secret Code and mini-chunking further extends this thinking. It is crucial that students have fluency and flexibility with number facts to 12 in the first instance and then to 20 as all later operations are built around these. Fluency with these facts will free up working memory to focus on harder sums as well as the thinking required when problem-solving. The variety of activities and games presented here are in line with the work of Delazer who says that automaticity should be reached through understanding of numerical relations, achieved by thinking about number strategies.
There is an accompanying set of cards for the numbers 0 - 10 which can be purchased separately for $16.50 or bundled with this book for a combined price of $44.