Lessons are carefully designed and structured to develop the necessary small conceptual steps for mastery. Only a single concept is developed each lesson. For example, adding fractions with same
denominator is not complicated by cancelling or dealing with mixed fractions.
Examples are chosen carefully to highlight the important conceptual ideas and tasks are chosen to provide pupils with intelligent practice.
Source  Guidance/Examples/Links/Stimuli 
NCETM Calculation Guidance  This document summarises and synthesises the discussions that took place between teachers who were part of the Shanghai/England primary exchange in 2014. It is not intended
to be a calculation policy as such; rather, it could sit alongside a school’s existing policy, and the ideas captured here (which are indicative and not exhaustive) could inform and enhance teaching
across all primary key stages.

Calculation Policy  By White Rose Maths Hub

Teaching for Mastery Document  A document by Annette Durkin from Whitehill Primary School about teaching for mastery in her school and how to develop deep understanding. 
NCETM Videos (Primary)  A collection of videos from NCETM on Youtube.

NCETM Videos to Support Mastery  From Dr Debbie Morgan and a Y3 class focusing on the 6 times table at Two Mile Ash School.

Developing Number Sense  A video by Jo Boaler on what we mean by number sense.

Example Shanghai Powerpoint files  A series of slides from visiting Shanghai teachers showing how examples were carefully crafted for different lessons. Collection of lessons on multiplication and division
with 2digit numbers fractions and decimals as well as addition and subtraction of fractions.

The Answer is Just the Beginning  A nice powerpoint from K Crozier (Eynesbury Primary School) about how to explore concepts in depth 
Y2 and Y6 Problems  from @WRMathshub. Series of reasoning problems published throughout March 2016.

KS1 Reasoning Problems KS2 Reasoning Problems KS4 Reasoning Problems 
from @WRMathsHub All White Rose Maths Hub resources via TES 
NCETM National Curriculum Resource Tool  The National Curriculum for Mathematics Resource Tool by NCETM gives guidance on progression and glossaries.

GCSE Problem Solving PPT  By @EJMaths based on the AQA GCSE Problem Solving Booklet.

Generic Reasoning Structures Unit Questioning Script Always Sometimes Never Classifying Planning for Different Questions Blooms Style Questions 
A selection of resources used in the Maths Hubs National KS3 Reasoning Project. 
NCETM Multiplicative Reasoning Materials  A suggested programme of professional development (PD) using the materials in this microsite. It is designed as an integrated series of workshops for KS3 teachers with associated lessons for KS3 classes. 
Key Understanding in Mathematics Learning  A series of articles by the Nuffield Foundation on learning and maths. 
Fractions Topic Breakdown  An example of how a topic can be broken down into a sequence of lessons by Surrey Plus Maths Hub. 
Progression in U+U addition facts  A table of addition facts up to 10+10, with suggested teaching sequence. With explanation 