When a giant elephant arrives as a birthday present for the prime minister of Han, his 6-year-old prodigy son, Cao Chong, orchestrates a plan to measure the beast’s weight.
Amazed by its size, spectators begin to place wagers on the elephant’s enormous weight. But without a scale large enough and strong enough to withstand the animal’s hefty mass, a challenge is presented to the prime minister’s advisers. Much deliberation ensues, and when a suggestion to slice the elephant into smaller pieces to fit on a regular scale is made, Chong intervenes with a more clever and ingenious plan. The mathematical puzzle is deftly explained in a story based on ancient Chinese history. Chong places the elephant in a boat, marks a water line on the outside of the boat, replaces the elephant with as many rocks as needed to lower the boat to the same water level and combines the principal of buoyancy with the total volume of rocks to calculate the elephant’s weight. Black-outlined colorful paintings provide a lush backdrop for the story’s circa–200 C.E. China setting, with royal characters in long robes and bejeweled crowns. An addendum includes well-defined activities for understanding buoyancy and scale measurement, a succinct history and geography of the Han Dynasty, and a biography of Cao Chong.
Nicely produced and balanced in its instructive approach. (Picture book. 5-8)