Useful Websites

Mathsbot is a great site for online manipulatives, question generators and much more.  “I use this site all the time”  – Jayne Webster – Secondary Teacher and Mastery Specialist
Each pack covers subject knowledge, teaching approaches, misconceptions and resources.  Very useful for PD with departments in Primary and Secondary.  From the creator of Resourceaholic 

Increasingly Difficult Questions

Variation Theory

Sequences and behaviour to enable mathematical thinking in the classroom – by Craig Barton @mrbartonmaths

Resourceaholic

Ideas and resources for teaching secondary school mathematics.

Dr Frost Maths

Good examples of procedural variation and intelligent practice.
EEDI.com The evolution of Diagnostic Questions – Craig Barton Watch the introduction video
More-same-less grids are a great way to make sure pupils are thinking while they practice, rather than just mechanically repeating the same thing.

Nonexamples.com

New from the creator of MathsBot. The idea is based on a Freyer model and there are good examples of standard, non standard and non examples – Variation

Goal Free Problems

GFP have been proven to support pupils in improving their knowledge and understanding by removing the cognitive load of the goal and therefore not prompting means-end analysis of a problem. 

Thinking Blocks

Thinking Blocks from MathPlayground is an excellent interactive bar modelling tool.  I have used it with Primary and Secondary.