The larger text and carefully controlled language level make the pages more accessible for lower achievers. More regular in-text questions and the end-of-spread questions build up pupils' knowledge - and confidence - throughout the lesson. Red and Green books have identical pagination, so you can use them side by side in a mixed-ability class.

The parallel higher level Red books in the Catalyst series use the same format as the Green books. This text also includes hands-on activities, summaries, and in-text questions to help pupils consolidate their knowledge.