TAN TRICKS I^{TM}
Polytans of sizes 1, 2, and 4 fill a square 5½" tray. Each size has its own color. There is an extra piece of the unit size triangle, 3 ditans and 14 tetratans. The tray is a deceptive shape. It is not truly a square but a diamond. The grid is diagonal within the frame. Tan Tricks I and Tan Tricks II, below, are one integral set and are sold as a combo, although packaged and playable individually. A 5piece subset of the tetratans presents a special activity of finding symmetrical combinations. Tan Tricks I is recommended for ages 10 to adult. Value alone, $29 
TAN TRICKS II^{TM}
The 4 tritans and 30 pentatans fill an 8½" square tray. In this case the grid lies squarely within the tray, and the hypotenuse in any piece will plot diagonally. It is no mean feat to solve it so that the tritans form a connected group. This set is sold as a combo with Tan Tricks I, although packaged and playable separately. For persistent puzzlers, ages 12 to adult. Value alone, $65 The combo, both sets together, colorcoordinated so all 5 sizes have their own color, $94 
TAN TRICKS III 
TAN TRICKS III^{TM}
The grand array of 107 hexatans has an extra plug made of 6 singles that can duplicate the shape of any hexatan. We show them making the symmetrical "house" at the very center (solution by Anneke Treep of the Netherlands). They could form other shapes as well or be split up and placed anywhere within the tray. The "house" is the most compact symmetrical plug that allows the whole tray to be filled. With it at the center took almost 40 hours to solve by hand. An even more symmetrical hexatan, the stretched hexagon, has been proven to make it impossible to fill the whole tray when it is the duplicate. See also a remarkable triangular shape solved by Nick Maeder. The 16x16" tray comes with a clear lid. For hardiest solvers only. $195

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