Robotics is easily taught to primary or high school aged students via means of the commercial interfaces on the market.

The two best known are the Lego Mindstorms kits and the Fischertecknik

I have an extensive set of resources on the LEGO blocks mostly based around the RoboCup Global Competition.
Here is a sample.

As the Fischertechnik materials are better supported for international schools in Hong Kong and the region, I am beginning to collect materials on these.

It looks like there are some great resources available on the US Fischertechnik website.