1. Young Mathematicians at work
Organizing and Collecting
The Number System

2. Overview
The idea of taking inventory is brought to the classroom from the story of the Masloppy family.
The concept of place value is developed as the children pack objects into groups of ten and study patterns in the data.
Children will begin to unitize - to count groups and objects at the same time.

3. Big Ideas
This unit is designed to encourage the development of some the big ideas underlying early number sense:
Compensation and equivalence
Unitizing
Place determines value
Commutativity and associativity
Place value patterns occur when making and adding
on groups of ten

4. Strategies You will notice that children use many strategies:
Using synchrony and one-to-one tagging
Counting on and counting backward
Skip-counting
Using the five- and ten-structures
Making ten
Keeping one addend whole, using landmark numbers, and/or taking leaps of ten
splitting

5. Mathematical Modeling
Model of the situation
Model of children’s strategies
Model as a tool for thinking

6. Presented by Audra Marsalia Brazos ISD Carla Henson Buffalo ISD
Beth Wiggins Snook ISD
Pat Duell Kennard ISD
Susan Bohan ESC 6