Pocket PUZZLE 1 - RICHTER — ARTOYA Learning Hub

Watch

See it come together

Assembly video coming — scan again after the next production run.

Read

The leaflet in the box

The same leaflet that comes with the kit, English on one side, French on the other. Free to download and print.

Download the leaflet (PDF)

ARTOYA_LEAFLET_AV0118113.pdf — 198 × 298 mm, EN/FR

Learn

Four ways in

Anchor Puzzle / Kopfzerbrecher / Le Casse-Tête Persan — page 17 of the Anker building-set pattern book 'Vorlagen Großkaliber Neue Folge 2', showing the puzzle box, the seven-piece square and four figures — F. Ad. Richter & Cie, Rudolstadt (anonymous company artwork) — February 1907 edition (ankerstein.ch: 'Ausgabe Februar 1907'); IA record says c. 1900 — Internet Archive (folkscanomy_images), scan from the Club of Anker Friends archive, ankerstein.ch/archiv/Vorlagen/GK-NF/02/072/17.JPG — anchor-puzzle-richters-toys-richter-friedrich-adolf-1846-1910 (1269 × 886)

A Timeless History

A craze before the crossword. The seven-piece square appeared in China around 1800; books of figures were on sale there by 1815, and a pair of them reached Philadelphia in 1816. In two years London, Paris and Copenhagen were hooked. In Germany, Friedrich Adolf Richter of Rudolstadt cast the pieces in artificial stone from 1890 and sold them as the Kopfzerbrecher, the Anchor Puzzle — first of some 36 stone puzzles.

SourceWikipedia, Tangram (citing J. Slocum, The Tangram Book, 2003) · Club van Ankervrienden, The history of Anker Stones · Lilly Library, Indiana University · Image: F. Ad. Richter & Cie, Anker pattern book, 1907 (PD)

Convex tangram shapes — all thirteen convex figures that can be made with the seven tangram pieces (vector diagram, rendered to 1400 × 1050 on white) — László Németh (Wikimedia Commons user), own work — 2014-06-05 — Wikimedia Commons — File:Convex tangram shapes.svg

Science In Action

Area — every figure uses all the pieces, so every solution has exactly the same area as the square • Angles — tangram corners are only 45°, 90° and 135°, which is why the outlines look so alike • Counting — with seven pieces there are only 13 convex shapes, proved in 1942, but thousands of figures • Search — Archimedes' 14-piece square has 536 distinct solutions; a computer found them in 2003

SourceWolfram MathWorld, Tangram and Stomachion · Wang & Hsiung, American Mathematical Monthly 49 (1942) · Image: the 13 convex tangrams, L. Németh — Wikimedia Commons (CC0)

Ch'i ch'iao hsin p'u : ch'i chiao t'u chieh (Qiqiao xinpu) — Chinese tangram book, woodblock print; two leaves composed side by side: outline figures (dragon gate, bird, crab, peach) and solved figures in black — Anonymous; publisher Fu Wen T'ang, China — 1816 — Princeton Theological Seminary Library, via Internet Archive (pages 0090 and 0110 of the scan) — chichiaohsinpuch00unse_1

Arts

Silhouettes with names. The Chinese books did not print solutions first: each page showed black outlines only — a bell, a vase, a dragon gate, a crab — and the solver had to find the cuts. The 1816 woodblock book Qiqiao xinpu, 'New patterns of the seven clever pieces', still reads like a picture gallery. Two centuries later designers still draw with the same seven pieces.

SourceCh'i ch'iao hsin p'u, Fu Wen T'ang, 1816 — Princeton Theological Seminary Library · Rijksmuseum RP-P-2004-482 (1826 edition) · Image: Internet Archive (PD)

Magnetic tangram — coloured tangram pieces on a classroom board — Fumikas Sagisavas (Wikimedia Commons user), own work — 2024-07-30 — Wikimedia Commons — File:Magnetic tangram.jpg (4000 × 3000)

Applications Today

Classrooms — tangrams teach fractions, symmetry and area in primary schools around the world • Cutting sheets — fitting flat parts on a board without waste is the same puzzle, solved by software • Rudolstadt — the Anker factory was refounded in 1995 and still presses the stone Kopfzerbrecher

SourceWikipedia, Anchor Stone Blocks and Richter (toy company) · Anker Steinbaukasten GmbH, Rudolstadt · Image: magnetic tangram on a classroom board — Wikimedia Commons (CC0)

Poe's ivory tangram — New York Public Library

Did you know?

Edgar Allan Poe owned one.

The New York Public Library keeps a carved ivory tangram that Poe gave to a neighbour, Miss Sarah Miller, at Fordham in the 1840s.

One more thing

Only 13 convex shapes can be made with the seven tangram pieces — a theorem proved in 1942 by Fu Traing Wang and Chuan-Chih Hsiung.

SourceWang & Hsiung, 'A theorem on the tangram', American Mathematical Monthly 49 (1942); Wolfram MathWorld, Tangram

Richter bought the stone recipe from the Lilienthal brothers in 1880; in 1883 he sold 42,000 building sets.

Go deeper

The long read

A two-to-three-page article with more images and full explanations — printable. Coming for this model.

Build

How it comes together

Every part is cut and marked on the board; full instructions are on the sheet in the box. Once built, it stays built.

1

READ THE SHEET

Take your time — every detail counts. Check all the pieces are on the board.

2

ONE PIECE AT A TIME

Press out each piece only when the sheet calls for it.

3

THE TRAY

Base plate turned over, the two short rails, then the two long rails.

4

PIECES AND LID

Ten puzzle pieces into the tray, then the lattice lid slides on top.

5

PAINT LAST

Once it stands — or keep it plain. No two are alike.

What it will not do

A puzzle, not a proof. Ten pieces, one rectangle, one tray. The lines on the pieces are engraved, not cut — no piece splits apart. Wood has a little play: a piece that 'almost' fits is not in, and the lid closes only when all ten are.

What it will give you

Why ten pieces are so hard to put back — area never changes when shape does, the angles must add up at every corner, and a tray leaves no room for 'nearly'.