Links for all the resources mentioned in my ATM 2021 Conference session:
Great Teaching toolkit: Evidence review – complete report
Examination Board Teaching Resources and 16+ Resources
White Rose Secondary Resources including Complete Secondary Small Steps
Building Blocks – Andy Lutwyche
Diagnostic Questions Diagnostic Question a Day
Spot the mistake resources including Erica’s Errors and Clumsy Clive from Andy Lutwyche
Show that… and What was the question? from Andy Lutwyche

Use of Technology including PhET Simulations and Open Middle problems in GeoGebra
(note there are numerous GeoGebra resources linked to GCSE and A Level)
Distributive Property: Open Middle Theme

Loughborough University Self Explanation Training
and from The Learning Scientists – Self-Explanation as a Study Strategy for Math
The Standards Unit (all resources) including Malcolm Swan’s Improving Learning in Mathematics
Negative Numbers – a roundup of resources on directed numbers to make this topic clear for students, including some excellent visuals.

Prime Factorisation using Prime Factor Tiles – Starting Points Maths
m4ths.com GCSE resources (scroll right down the page for the misconceptions resource)
NonExamples.com Frayer-Model.co.uk

Illustrated Mathematics Dictionary from Mathisfun!
See also Reference for Jenny Eather’s dictionary and posters
On CIMT there are interactive tutorials for Years 7, 8 and 9
Berwick Maths – The Centre of Worked Examples
From Mrs Jaggers Going for Gold (all resources) is a brilliant set of questions testing skills that appear on both foundation and higher tier papers. You can choose from Bronze, Silver or Gold; the papers have the same questions, but with varying amounts of scaffolding. Worked solutions are provided. Preview the papers on Jaggers Maths.

AlgebraByExample and Math by Example
Colour in Mathematics – the use of colour to add clarity

Here’s the diagram…what’s the question?
Variation Theory – Craig Barton
Nrich Mathematical Etudes and Purposeful Practice
Colin Foster – including Mathematical Etudes
Nrich – Multiple Representations
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.
Calculators – including Equations – Linear and Quadratic

Transum – Topic Index
Transum Maths Map (Students)
Transum Advanced Starters

Further Reading
Activating Hard Thinking – Class Teaching – Durrington Research School
Rosenshine’s Principles of Instruction
Highly recommended is the Retrieval Practice website from Dr Pooja K. Agarwal.