曹冲称象》（出自《三国志·魏书·邓哀王冲传》）

邓哀王冲字仓舒。少聪察岐嶷，生五六岁，智意所及，有若成人之智。时孙权曾致巨象，太祖欲知其斤重，访之群下，咸莫能出其理。冲曰：“置象大船之上，而刻其水痕所至，称物以载之，则校可知矣。”太祖大悦，即施行焉。

"Cao Chong Weighs an Elephant"

Cao Chong, styled Cangshu, was a remarkably¹ intelligent child. By the age of five or six, his wisdom rivaled that of an adult. Once, Sun Quan sent a giant elephant as a gift to Cao Cao (Cao Chong's father and the ruler of Wei). Curious about the elephant’s weight, Cao Cao asked his officials for a solution, but none could devise a method.

Young Cao Chong then said:

"Place the elephant on a large boat and mark the water level on the hull². Then replace the elephant with smaller weights (e.g., stones) until the boat sinks to the same mark. By weighing the total items added, we’ll know the elephant’s weight."

Delighted, Cao Cao ordered the method to be implemented³, and it proved successful.