Rich scientific and cultural knowledge is carried with these Chinese traditional toys. For example, bamboo-copter (竹蜻蜓 ”bamboo dragonfly”) invented around 400BC, essentially consists of a propeller on a stick, and rolling the stick in the right direction spins the propeller, causing the toy to “take off” when it is let go. This toy made its way to Europe and is depicted in a 1463 European painting. It is said to have inspired the early design of flying machines.
Toys that were simply made may have creative ways of playing. In the game of Puffing Paper Frog（噴田蛤仔）for example, players first fold paper frogs and then place them in confrontation. Each player tries to puff into his/her own frog to jerk it into smashing the opponent’s frog.
Puzzles are toys made especially as intellectual challenges and can be extremely engrossing. Figure 2 shows some intellectual puzzles well-known since the early history of China.
Many of these puzzles have deep knowledge of mathematics combined with logical reasoning. For instance, Seven-piece Tangram is not only able to train on the concepts of geometry but also an ability to think out of the box. Nine Connected Rings is a game about binary systems and can be used to learn summations and mathematical induction.