Counting Principles and Quantity Principles
Stable Order: counting sequence remains consistent
Order Irrelevance: you can start counting with any object in a set and that the total will always be the same, regardless of which item you start with
Conservation: the total count for a set remains the same regardless of how the objects are spaced
Abstraction: quantity can be represented by a variety of things (3 cats; 3 continents; 3 emotions, etc.) 3 small objects is the same as 3 large objects
One-to-One Correspondence: each object is only given one count (touch counting)
Cardinality: the last item counted in a set represents the total number of items in that set
Movement is Magnitude: as one moves up or down the counting sequence, the quantity counted increases or decreases
Unitizing: a set of objects can be seen simultaneously as 1 set and, say, 10 objects (10 pennies = 1 dime; 5 fingers = 1 hand)
Hierarchical Inclusion: Understanding that all numbers preceding a number can be or are systematically included in the value of another selected number. So in a group of 5 there's also a group of 4, and a group of 3 and 2 and 1 is embedded it there.
Subitizing: In general, subitizing is the ability to "see" or visualize a small amount of objects and know how many there are without counting. (more detail can be found in the subitizing section of this website)
Check more at: What is Subitizing?
(Kyle Pearce & Jon Orr on The Principles of Counting and Quantity )
• Numbers represent a common organizational structure that we use in our lives and in our world to communicate/represent value.
• Numbers can be taken apart (decomposed) and put together (recomposed).
• The ability to decompose and recompose is a useful strategy in all aspects of mathematical thinking.
• We can use objects, pictures, symbols, and/or words to represent number and quantity.
• There are many ways to count. Each way to count has a proper sequence. (stable order)
• Quantity can be represented in many ways. (Order Irrelevance)
• The same quantity can look different (abstraction).
• We are learning that as we move up or down the counting sequence, the quantity increases or decreases by the number we are counting by (magnitude).