Browse Items (176 total)
- Tags: G4G13
Sort by:
Surprise! Puzzles
A small booklet of 20 math puzzles that involve the element of surprise. Some appear to lack sufficient information to solve; others run counter to one's intuition as to what the answer should be.
Tags: Exchange Gift, G4G13
4 x 13
There are 52 cards in a standard deck of playing cards: four suits of 13 cards each. To design a deck of cards, one needs to establish the four suits, each with its own symbol and/or concept, and find a logic for generating the 13 cards in each suit,…
Tags: Exchange Gift, G4G13
Lights & Spheres
A 7cm green plastic sphere with a surface of conical projections, otherwise known as a Cando Massage Ball.
Titanium LED keychain flashlights: I will ship 200 with white LED, 100 with red, blue and green LEDs. Each attendee will receive one light…
Titanium LED keychain flashlights: I will ship 200 with white LED, 100 with red, blue and green LEDs. Each attendee will receive one light…
Tags: Exchange Gift, G4G13, green plastic spiky ball, key chain, LEDs
Cavalieri Content Cups
Just as 13 breaks up nicely as the sum of 8 and 5, so too does the (volume of a) cylinder break up nicely as the sum of a cone and hemisphere, a fact we have seen demonstrated at previous Gatherings in vivid ways. But the one-diagram proof of this…
Spiram Siderum
A craft kit with all parts needed to crate a tiny kinetic sculpture based on the physics of equilibrium, magnetic force, and angular momentum.
Tags: Art, G4G13, magnetism, PhysicsFun