The Starting Point – Number Sense, Addition and Subtraction

Once students gain number sense and become comfortable with counting and associating quantities with numbers, the notion of how far apart a pair of numbers are introduced, which naturally leads to the concepts of addition and subtraction.

Number sense can refer to “an intuitive understanding of numbers, their magnitude, relationships, and how they are affected by operations”, for example the ability to understand quantities and concepts like more and less.

This skill is then extended to the understanding how far two numbers are separated, which leads naturally to the concepts of adding and subtracting. This is introduced in steps, starting with numbers within 10 (i.e. within single digit numbers up to 10), then extending to more place values, numbers to 20, 40 and 100 (first grade), then to 1,000 (second grade), 10,000 (third grade), and onto higher orders in grades four and five.

Developing these foundation skills takes up the main part of the first and second grade elementary mathematics curriculum – developing number sense, understanding the two basic operations, and extending to multiple place values. It is one of the most important part of a student’s learning in elementary school.