Use models (such as discrete objects, connecting cubes, and number lines) to represent “part-whole,” “adding to,” “taking away from,” and “comparing to” situations to develop understanding of the meaning of addition and subtraction. 0106.2.10

Links verified on 12/13/2009

1. Base 10 - build blocks to create numbers with tens and ones - reinforces tally marks, number line, base ten blocks, and allows hundred blocks for advanced students
2. Base 10 Blocks - exploring whole decimal numbers with blocks
3. Compare Numbers - short interactive lesson using place value and number blocks
4. Help Caillou Build a Train Track - When Callilou asks "Do you want to play with me?", click on the train. Match patterns of track pieces to let the passengers get to the train station.
5. National Library of Virtual Manipulatives
   1. Number & Operations [Grades Pre-K-2]
   2. Algebra [Grades Pre-K-2]
   3. Geometry [Grades Pre-K-2]
   4. Measurement [Grades Pre-K-2]
   5. Data Analysis & Probability [Grades Pre-K-2]
6. Trading Game - explore regrouping using place value blocks [designed for 3rd grade]