Expert mathematicians stumped by simple subtractions

"These problems were presented in two different types of contexts. Half of the problems involved calculating the number of animals in a pack, the price of a meal in a restaurant or the weight of a stack of dictionaries (elements that can be grouped together as sets).

*For example: “Sarah has 14 animals: cats and dogs. Mehdi has two cats fewer than Sarah, and as many dogs. How many animals does Mehdi have?” The second type of problems required calculating how long it takes to build a cathedral, to which floor an elevator arrives or how tall a Smurf is (statements that can be represented along a horizontal or vertical axis). *

For example: “When Lazy Smurf climbs onto a table, he attains 14 cm. Grumpy Smurf is 2 cm shorter than Lazy Smurf, and he climbs onto the same table. What height does Grumpy Smurf attain.”*

IMO, the mathematicians were confused by the absence of a question mark at the end of each question.

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I wonder if there were some language issues. “He attains 14cm” - what does it mean for someone to attain a distance? It would be clearer if they said “he attains a height of 14cm above the ground”, if that’s what they mean. As written, I was left wondering whether they meant he had moved up 14cm as the result of climbing on the table.

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I noticed that too. The language is stiff and awkward. The study was conducted in Switzerland so I assume this is a clumsy translation. “Attain” is not a common word. I was alluding to that in my snide comment about missing question marks. But the question remains since mathematicians, from their experience, will read such problems differently. When they write such definitions for each other, they try to be be clear and helpful. They don’t set traps by adding irrelevant information that suggests a different problem.


It might just be the testing environment and the fact that with word problems, mathematicians probably check for validity as well.

There is nothing that keeps Sarah from having 13 dogs and 1 cat given the phrasing of the problem. Now Mehdi ends up with -1 cats. So now you start looking for all kinds of ways that this could be a trick question.

Basically, comes down to awful wording which makes you assume some sort of Facebook meme trick question problem. At least more than this would have to do with clustering or spacial representation.

They should have done this with simple math formulas and in between messed with their world understanding in a different way.

Mathematicians don’t set traps but Math Professors do. This has always struck me as a sad state of affairs. Exams designed to confuse rather than enlighten. The desire to enforce a grade curve never made me think highly of university as a place of “higher education”.


Depends a bit which side of the pond you’re on… luckily, no common core math outside of North America.

The problem is things like this… that’s like giving an experienced speed cuber a Japanese color scheme and then watch him mess up his time: