14 Apr

Call for Puzzles

Hey, I have recently become problem editor for the undergraduate Math Horizons magazine of the Mathematical Association of America. So I’d love if you have problems/mathematical puzzles to submit to the column. The official submission blurb follows, and of course you will be credited in the Magazine. The Playground features problems for students at the […]

10 Apr

Gengzhi Goblets

One might think that having produced prototypes of the Gengzhi Goblets, our work is just about done to produce sufficient quantity (roughly 300 of each) to serve as G4G13 giveaways. The question comes down to materials and expense. If the Gengzhi Goblets are actually to be used as measuring cups, then they need to be […]

10 Apr

Portion Prototyping

By exploring the theory, the following shapes arose as a natural G4G13 giveaway: a regular 13-gon prism, a cup with octagonal cross sections whose octagon sides scaled with height as √(1-h³), and a cup with pentagonal cross sections with sides scaling as h3/2. The largest octagon and pentagon would be sized to have the same […]

10 Apr

Archimedean Variations

So I had zeroed in on the proof of the Archimedean volume relationship as the source of my giveaway for G4G13. But how to create an interesting variation? The first thing to notice is that the function of h that appears in the proof in the cross-sectional area of of the cone, namely h², could […]

09 Apr

Mathematical Free Association

So it became time to decide on Studio Infinity’s giveaway at the 13th Gathering for Gardner (G4G13). By tradition, at least, it’s considered a plus for giveaways to connect with the number of the conference — 13 in this case. So this mathematical free association starts with the number 13. What thoughts does 13 evoke? […]

05 Apr


In addition to the main, planned build at the Golden Gate STEM Fair, and thanks to donations of materials from Primed Minds, there was also a do-it-yourself/take-home table at the STEM Fair. Participants produced such towers as this one: However, this column isn’t mainly about the inquisitive fun that participants at the take-home table had, […]

05 Apr

GGSF: Prep

A brief post about the importance of prepping and prototyping for a build, and a couple of things that came up in the prep for the Golden Gate STEM Fair event. First, there’s just the sheer volume of supplies for such an event. Here are lots of beads getting outfitted with twist ties, for example. […]