
Developing Number Sense: Principles of Counting
All concepts of number sense need to be actively taught.
The one-to-one correspondence principle ensures we accurately count objects one at a time.

Movement is Magnitude Principle
When children understand that when you count in a stable order, each time you count an object it is increasing by one. In contrast, if you are counting backwards, in stable order, each time you are decreasing by one.
This concept can also be applied to skip counting. So, if you are counting by 2’s you know that you are constantly adding or decreasing the number by two.
Practice
Building towers with blocks, lego or any type of manipulative that is of a consistent height helps teach kids the visual concept of movement is magnitude.
Graphing with charts is a visual representation where children can see this concept. Especially when the topic is related to their personal lives. For example, how many people walk to school versus how many people take the bus?
For children ready for skip counting, moving manipulatives two at a time while they are counting can help them understand the consistency of this principle.
This number wall is often what I use to represent number sense with my students. At the bottom of the posters, we represent movement is magnitude. We usually use photos of our students, as represented in this pictures above.

Click here to see other number sense principles and activities to support number sense development!
Number Sense Freebie
I use this landscape of learning to know where each student is developmentally with number sense and to target small groups with students who have similar needs. Click on the image to be able to download this!
