Book excerpt: Essential Mathematics For The Australian Curriculum Year 9 Essential Mathematics for the Australian Curriculum builds on established learning sequences and teaching methods to provide an authoritative and practical interpretation of all content strands, sub strands and content descriptions. It also covers essential prior knowledge and includes some extension topics. The essential foundations of the series: The three interconnected content strands are incorporated into 11 units of work that can be completed in the school year Let's Start activities provide context and foundation for topics Every question is grouped according to the four proficiency strands of the new Australian Curriculum: Understanding, Fluency, Problem-solving and Reasoning Problem-solving and Reasoning questions are included in every exercise Enrichment questions in each exercise, and investigations, challenges and puzzles in every chapter reflect curriculum aims by extending students in depth Literacy and numeracy skills, thinking skills, creativity and ICT activities (including dynamic geometry and calculator activities) are incorporated and encouraged in every chapter.