Dr. Amanda VanDerHeyden is a mathematics education researcher, founder of Spring Math and a policy Adviser who is also involved in new Science of Math initiative. In this episode, Amanda talks to Greg Ashman about how she developed an interest in class-wide maths intervention and what makes such an intervention successful. Amanda and Greg also discuss use of data, explicit teaching and how to deal with the arguments of the 'other side', including a discussion of procedural fluency versus conceptual understanding, productive struggle and the idea that timed tests cause maths anxiety.