Eric discovers that the mass and size of an object are not at all the same. All you need to prove it is something heavy and a LOT of something light! It's not magic ... it's mathematical! The pedagogical side: This segment discusses the mass of an object and how it can be measured using tools (eg scales, which illustrate concepts of larger, smaller or equal), units ( kilograms) and volume (the space occupied). We also present the notion of equality, represented by a scale.