We tried to be friendly and unintimidating and, if asked, we explained with a bit of embarrassment that it had to do with a bet. Many just assumed we needed to know what a “sphere” was, though. We might have said we weren’t looking for a fancy answer, I’m not sure. (Ideal, if you want to repeat this experiment, would be to get a child to do the asking and to say it’s for their homework or something.) I don’t clearly remember what wrong answers we got; it’s possible that someone said “Does it mean circle-shaped?” but couldn’t give follow-up detail and someone else, who looked rather blank, said something like “Um. ‘Sphere?’ Do you know what that is, Frank?” and then asked the man she was with, who answered correctly.
Like SarahC, I used to tutor folks who were en route to becoming high school math teachers, and who had to pass a math exam to be allowed to teach. Many of them genuinely didn’t know what a sphere was, in the sense that often their eyes would light up if I told them that “sphere” meant “ball-shaped” (and, if I didn’t, they would memorize the formula for the volume of a sphere but would often not know they could apply it to estimate the volume of a ball). This was one of those pieces that I initially didn’t realize I needed to teach. Other such pieces included e.g. the fact that a “square centimeter” is a 1-cm by 1-cm square, that “area” is about how many such squares it takes to cover a given shape, that one can find the area of a compound shape by adding or subtracting the area of the components, and that there is a difference in meaning between “If A, then B” and “If B, then A”.
We tried to be friendly and unintimidating and, if asked, we explained with a bit of embarrassment that it had to do with a bet. Many just assumed we needed to know what a “sphere” was, though. We might have said we weren’t looking for a fancy answer, I’m not sure. (Ideal, if you want to repeat this experiment, would be to get a child to do the asking and to say it’s for their homework or something.) I don’t clearly remember what wrong answers we got; it’s possible that someone said “Does it mean circle-shaped?” but couldn’t give follow-up detail and someone else, who looked rather blank, said something like “Um. ‘Sphere?’ Do you know what that is, Frank?” and then asked the man she was with, who answered correctly.
Like SarahC, I used to tutor folks who were en route to becoming high school math teachers, and who had to pass a math exam to be allowed to teach. Many of them genuinely didn’t know what a sphere was, in the sense that often their eyes would light up if I told them that “sphere” meant “ball-shaped” (and, if I didn’t, they would memorize the formula for the volume of a sphere but would often not know they could apply it to estimate the volume of a ball). This was one of those pieces that I initially didn’t realize I needed to teach. Other such pieces included e.g. the fact that a “square centimeter” is a 1-cm by 1-cm square, that “area” is about how many such squares it takes to cover a given shape, that one can find the area of a compound shape by adding or subtracting the area of the components, and that there is a difference in meaning between “If A, then B” and “If B, then A”.