Fundamental Math Skill:
 Developing Proficiency with Operations: Performing calculations with ease, precision, and consistency and with a general understanding of number and operations, number properties, and their appropriate application in problemsolving.
– Focusing on the Fundamentals of Math – A Teacher’s Guide, p.2
Video Selections
These curated videos have been selected to help you gain a deeper understanding of the above selection from “Focusing on the Fundamentals of Math – A Teachers Guide”.
Thinking About Proficiency With OperationsProficiency With Addition And SubtractionProficiency With Multiplication And DivisionProficiency: Proportional Reasoning Ratios & RatesFractions Proficiency Through Spatial Reasoning
All Models are Not Created Equal  Cathy Fosnot (3:21)
From "Leaders in Educational Thought: Special Edition on Mathematics (2013)"
Composing and Decomposing: Overall Description (1:17)
From "Spatial Reasoning in Number Sense and Numeration"
Scaling Up or Down: Overall Description (1:47)
From "Spatial Reasoning in Number Sense and Numeration"
Text Resources
This curated list of documents have been selected to help you gain a deeper understanding of the above selection from “Focusing on the Fundamentals of Math – A Teachers Guide”. Each link will take you directly to the relevant section within the document.
A Guide to Effective Instruction in Mathematics, K6, Number Sense and Numeration Vol 1, The Big Ideas 

Differentiating Mathematics Instruction – Capacity Building Series 

Asking Effective Questions – Capacity Building Series 

The Mathematical Territory Between Direct Modelling and Proficiency, What Works 

Paying Attention to Spatial Reasoning 

Maximizing Student Mathematical Learning in the Early Years – Capacity Building Series 