TED Talks
Ted: Ted Ed: Why the Metric System Matters
For the majority of recorded human history, units like the weight of a grain or the length of a hand weren't exact and varied from place to place. Now, consistent measurements are such an integral part of our daily lives that it's hard...
E-learning for Kids
E Learning for Kids: Math: Market Place: Mass
On this interactive site students learn to use various units of mass to solve problems and put objects in order by their mass.