Virtual Manipulatives - interactive activities complete with lesson plans for teachers (Primary, Junior, Intermediate)
Addition, Subtraction, Multiplication and Division ,Rounding, Area, Square Root, Algebra, Fraction Inequalities, Addition, Subtraction, Multiplication and Division with Negative Numbers, Inequalities, Reducing Fractions, Multiplying and Reducing Fractions, Money, Geometric Shapes Learn your geometric terms! (Primary, Junior, Intermediate)
The Maths File Game Show from BBC Education - requires the Shockwave plugin. (Junior/Intermediate)
Investigating Tessellations Using Activity Pattern Blocks The on-line student activity is the Pattern Program. "This program consists of a panel where you can drag in four different types of shapes of nicely fitting sizes -- pattern blocks or manipulatives. Once inside the panel you can rotate them and move them."
Project Interactivate - Activities That Practice Function and Algebra Concepts - The activities are designed for either group or individual exploration for topics such as an introduction to functions, special properties of linear functions, graphs and the coordinate plane, and reading graphs. The activities are Java applets and as such require a java-capable browser. (Junior/Intermediate)
Patterns - from the Maths Year 2000 project