The third edition fully covers both Core and Extended content through the \’spiral\’ approach, where students build their previous learning as they progress through the course. In addition to wealth of practice questions and support for English as second language learners, we have included a number of projects to encourage students to put their theory into practice provided by NRICH – a collaboration between the Faculties of Mathematics and Education at the University of Cambridge. This print coursebook comes with a subscription to Cambridge Online Mathematics, our enhanced digital teaching and learning platform. Coursebook answers are available on Cambridge Go.