Each chapter treats a mathematical concept in-depth, with a series of tightly scaffolded lessons to gradually build students’ understandings. Each lesson starts with an explicit, teacher-led activity called Let’s Learn that models examples of mathematical thinking and problem-solving. This is followed by some ‘guided’ activities to allow students to apply their understandings in Let’s Do. At the end of lessons, there are some Let’s Practice activities so students are able to demonstrate their understandings and teachers are able to do immediate formative assessment. Many of the topics in PRIME go beyond those taught in the Australian curriculum at the same year level. Curriculum alignment is available.