GeoGebra is an interactive mathematics software suite for learning and teaching science, technology, engineering, and mathematics from primary school up to the university level.

Teachers and students can use GeoGebra as an aid in formulating and proving geometric conjectures.

GeoGebra's main features are:

• Interactive geometry and graphing environment (2D and 3D)

• Built-in spreadsheet

• Built-in computer algebra system (CAS)

• Built-in statistics and calculus tools

• Scripting hooks

• Large number of interactive learning and teaching resources at GeoGebra Materials.

Click here for GeoGebra.

ThinkingBlocks provides virtual manipulatives that are effective in improving students' understanding of fractions and ratios through the use of bar models.

Click here for Thinking Blocks.