How to try Mathematica demos?

1. Download and install the Mathematica player for free.
2. Go to the Wolfram Demonstration Project page to download a demo. You can find the Linear Algebra demos here.
3. Select a demo to try. For example, go to the 2D Vector Addition demo page.
4. Click the screenshot image and select "download live version with active controls" to download a *.nbp file.
5. Run the MathematicaPlayer and open a *.nbp file downloaded and try yourself!