Mass
Newton's definition-quanity of matter
The amount of matter that makes up an object
http://www.merriam-webster.com/dictionary/mass?show=1&t=1321201216
http://hyperphysics.phy-astr.gsu.edu/hbase/mass.html
http://en.wikipedia.org/wiki/Mass
http://www.physics.ucla.edu/k-6connection/Mass,w,d.htm
http://www.merriam-webster.com/dictionary/mass?show=1&t=1321201216
http://www.ehow.com/how_2090536_teach-geometric-mass-kids.html
Interactive
http://www.sciencejoywagon.com/explrsci/media/density.htm
http://ippex.pppl.gov/interactive/