# Category - Number Sense

## Unitizing – Principles of Counting and Quantity

Unitizing is the understanding that you can count a large group of items by counting smaller, equal groups of items from within the large group.

## Movement is Magnitude – Principles of Counting and Quantity

Movement is Magnitude is the counting and quantity principle that refers to the understanding that as you move up the counting sequence (or...

## Hierarchical Inclusion – Principles of Counting and Quantity

Hierarchical Inclusion is the counting and quantity principle that refers to understanding that all numbers preceding a number can be or are...

## Subitizing – Principles of Counting and Quantity

In general, subitizing is the ability to “see” or visualize a small amount of objects and know how many there are without counting. While this idea...

## Cardinality – Counting and Quantity Principles

Cardinality is the counting and quantity principle referring to the understanding that the last number used to count a group of objects represents...

## One-to-One Correspondence – Counting and Quantity Principles

One to One Correspondence is the counting and quantity principle referring to the understanding that each object in a group can be counted...

## Abstraction – Counting and Quantity

Abstraction is the counting and quantity principle referring to the understanding that we can count any collection of objects, whether tangible or...

## Conservation – Counting and Quantity Principles

Conservation is the counting and quantity principle referring to the understanding that the count for a set group of objects stays the same no matter...

## Order Irrelevance – Counting and Quantity Principles

The order in which items are counted is irrelevant. Students have an understanding of order irrelevance when they are able to count a group of items...

## Stable-Order – Principles of Counting and Quantity

The first principle of counting involves the student using a list of words to count in a repeatable order. This “stable list” must be at least as...