Dinosaur Deals

Mike and Andy arrive at the Dinosaur Card Trading Fair with a mission: trade up to the coveted T-rex card. The catch is that trades follow fixed equivalencies — four Stegosaurus cards equal one Triceratops, two Triceratops equal one Allosaurus — so the boys have to think carefully and move fast. Stuart J. Murphy buries a genuine math lesson about equivalent values inside a fast-moving, high-stakes narrative, and it works. Kevin O'Malley's energetic art keeps the energy up. The back-matter tips for parents and teachers make this as useful at home as in a classroom. The story does exist primarily as a vehicle for the math concept, and character depth is thin, but that's by design for the MathStart series. For kids just cracking the idea of equivalency, this is an excellent on-ramp.