SMP Interact is a major mathematics course for Key Stages 3 and 4. The Key Stage 3 books have been revised into a simpler structure that supports the Framework for Teaching Mathematics; Years 7, 8 and 9, both in its specific content and in its general interactive approach to teaching. All the materials have been fully trialled in the classroom, and working teachers from a wide variety of schools have been involved at all stages of writing, trialling, and improving. Book 7S is the first of three books leading to Key Stage 3 SATs at levels 4-6. It is accompanied by a Teacher's Guide and Resource Sheets, while a Practice book provides additional support questions for use either at home or in the classroom.