Don Steward has an extensive collection of activities to really make your students think and learn. Note the helpful topics menu on the right-hand side of the page. The example shown above can be found under Algebra Misconceptions.
With changes to examinations at both GCSE (UK examination taken at age 16) and A Level (UK examination taken at age 18), all the examination boards are offering help and support for teachers and students. Many excellent resources are available.
For example, we have Edexcel’s very helpful resources for teaching new content. For each topic, information, examples and exercises (with answers) are given.
These resources are very helpful with plenty of examples and exercises, a very thorough treatment of each topic.
Note the menu on the left; you can easily navigate these resources choosing the Content type. Looking at Classroom tests, for example, you will find a complete collection of tests with answers by topic for both Foundation and Higher tiers.
Similarly, from AQA we have their very helpful Bridging the Gap resources. These resources by topic are also useful for ideas to teach younger students. Further outstanding resources from AQA including the wonderful Problem Solving resource are detailed on this AQA GCSE page.
The Check in tests are excellent. Consider the language of functions for example, the first questions could be used with students as young as Year 7. Full details of the Check in tests can be found in the Teachers’ Guide. Each test is of a similar format in that Questions 1-5 cover procedural calculations (AO1), questions 6-8 require the ability to reason and communicate mathematically (AO2) and questions 9-10 relate to problem solving tasks (AO3). There is also an extension task. Very usefully (thank you OCR) the Check in tests are also available in Word Format.