For dino-lovers Mike and his little brother Andy, there's nothing as exciting as the Dinosaur Card Trading Fair. Andy's in heaven on his 7th birthday when Mom lets Mike take him for the very first time. Mike really wants a T. Rex card, but to get it he's going to have to trade. He needs three Allosaurus cards to get a T. Rex, but has only one. This is going take some wheeling and dealing. Helping children to comprehend the concept of equivalent values is key to their understanding of equations. Used with permission from Stuart J. Murphy.
MathStart 3: Dinosaur Deals (Equivalent Values)