There is the so-called [FCI test][1]. It contains a list of questions such that anyone who can speak will have an opinion. Based on the answers one can determine if the answerer knows elementary mechanics. I learned about this test from an interesting [lecture from Eric Mazur][2] describing an application of such a list. It seems that there are no analogous tests in mathematics. Did I miss something? Sergei Tabachnikov shared a couple of questions that might work: * One needs to peel potatoes. What is faster and why: peeling a pound of large or small potatoes? * Why does a reflection in a mirror interchange left and right, but not up and down? * Two people are walking down an escalator (that is moving down), counting their steps. Who will count more steps, the one who is moving faster or slower? >**Could you share more questions of this type?** Please make one question per answer. The questions should not use any professional jargon; **no graphs no formulas**; say, they could be asked in a kindergarten. I think it is possible to find such question for Euclidean geometry; I am not sure about other branches of mathematics. [1]: https://en.wikipedia.org/wiki/Force_Concept_Inventory [2]: https://www.youtube.com/watch?v=WwslBPj8GgI