AQA’s KS3-4 Bridging the Gap set of resources is excellent. Whilst originally designed to support teaching and learning for the cohorts of students who studied the 2007 Key Stage 3 Programme of Study and were preparing for the then new Mathematics GCSE it remains just as useful now.
The teaching materials provided in 9 ‘Pockets’ focus on the areas new to this current GCSE specification; the use of these at KS3 helps ensure students have the relevant pre-requisite knowledge to progress to the GCSE specification. For example, Pocket 2 on function notation introduces the formal f(x) notation.
The nine resource sets cover Fractions and ratio problems, Function notation, Graphs in real-life contexts, Iterative methods for solving equations numerically, Set notation, number lines and Venn diagrams, Number sequences, Direct and inverse proportion, Growth and decay, and Vectors.
Each set of resources has three sections; the first, developing understanding, includes class-based, teacher-led questions, Skills Builders are standard progressive worksheets that can be used to drill core skills in a particular area and Problem Solving Activities are Extension activities for paired work or small group work to develop problem-solving skills.
I have used many of these resources since they were first made available, for example, the resources introducing the concepts of using iterative methods to solve equations numerically in cases where an algebraic approach is not possible. I recommended these resources in my post on Iterative Methods originally written in May 2015, a post that remains popular.
The Teacher Guide includes in Section 3, five exemplar activities on mathematical proof and in Section 4 we have some suggested resources for embedding problem-solving activities throughout the mathematics curriculum. Included is a link to the classic Durham Maths Mysteries. AQA quite highlight the Directed Numbers mystery, where students must decide which number goes where on a 3×3 grid given thirteen cards each with a statement about directed numbers and how they lie on a 3 by 3 grid.
Staying with the subject of Bridging the Gap, see this post, Transition Time which looks at some resources for transition from GCSE to A Level and also resources to help prepare for University.