This book explains 'big ideas' in mathematics in simple terms supported by classroom examples to show how they can be applied in primary schools to enable learning. Carefully linked to the National Curriculum, it covers all the major concepts so you can develop your own mathematical subject knowledge and to give you the confidence to deepen your understanding of the children you teach. This second edition includes: · A new 'links with mastery' feature showing how to teach with mastery in mind · A new glossary of key terms · New big ideas and activities throughout