七巧板

The tangram is a dissection puzzle consisting of seven flat geometric pieces — called tans — cut from a square: five right triangles (two large, one medium, two small), one small square, and one parallelogram. All seven pieces must be used to form each figure, without overlapping. The Chinese name for the puzzle is 七巧板 (qī qiǎo bǎn), meaning 'seven clever boards' or 'seven skillful pieces,' a name that captures both the count and the nature of the challenge. The English word tangram is more puzzling than the puzzle itself: its etymology is genuinely uncertain. The most plausible theory connects it to the Cantonese t'ong (唐, meaning 'Chinese' or 'of the Tang Dynasty') plus the Greek-derived suffix -gram (something written or drawn). Another theory proposes it derives from the obsolete English word 'trangam,' meaning a trifle or trinket. Neither explanation is fully satisfying, and the word's first traceable appearances in print (around 1848) offer no clear origin story.

The puzzle's Chinese history begins in the late eighteenth century, during the Qing Dynasty. The earliest known Chinese tangram book dates to 1813, though the puzzle may have circulated for decades before that. Chinese puzzle-books of this period — called qiqiaoban books — showed hundreds of silhouettes to be formed from the seven pieces: people, animals, boats, letters, abstract patterns. The puzzle spread rapidly through Chinese intellectual circles as an elegant pastime combining geometry and aesthetics.

Tangrams reached Europe and America in the early nineteenth century, arriving on trade ships from China around the time of the Napoleonic Wars. Their sudden popularity was remarkable: by 1817, puzzle books were being published in France, Germany, England, and the United States. Napoleon Bonaparte was reported to be an enthusiast during his exile on Saint Helena; Lewis Carroll played with tangrams; Edgar Allan Poe mentioned them. The geometric simplicity of the seven pieces produced inexhaustible variety — thousands of distinct figures, each formed from the same shapes — which struck Western audiences as both mathematically interesting and aesthetically delightful.

The word 'tangram' appears to have emerged in English during the 1840s–1850s, somewhat after the puzzle's initial European popularity, and gradually displaced earlier English terms like 'Chinese puzzle.' It was then retroactively applied to all earlier discussions of the puzzle. Today tangram is the universal term in most Western languages, and the puzzle has become a staple of elementary mathematics education, used to teach geometry, spatial reasoning, and fractions. The qīqiǎobǎn of the Qing court now lives in kindergarten classrooms worldwide.