Number and Algebra
The commutative, associative and distributive laws allow some arithmetic problems to be completed without complicated calculations. In these resources different mental strategies are introduced. These are not only important for their practical role of performing arithmetic operations 'in our heads' but also to prepare students for working with variables in algebra.
The strategies discussed are far from exhaustive and it is important for each person to develop their own set of correct strategies, therefore reinforcing and enhancing their understanding of numbers and the laws of arithmetic.