I was surprised that the story of Gauss's schoolboy arithmetic tricks was the guy himself. Per Sartorius, Gauss "often related [the incident] in old age with amusement and relish". I suppose it makes sense. I cannot imagine biographers hunting down old schoolmates for stories without modern tools.
A lot of celebrity myths can be verified in 2022. Michael Jordan often recounted [0] that he was cut from his high school basketball team. Reporters found his high school coach who clarified that Michael was placed on junior varsity just like everyone else in his year[1].
Nice collection of versions of the 1+2+...+100 anecdote but I like Russell Impagliazzo's even more fictionalized set of examples best. The characters are Gauss and Grouse. Grouse was imho more interesting than Büttner.
If memory serves, I was at a middle-school It's Academic contest when the summation was attributed to Fibonacci. A mathematical version of "Victory has a thousand fathers"?
Popularity contests are infamous truth sources. Pythagoreans likely originated the "[equilateral] triangular" number formula, but an unpublished astronomical treatise by the Irish monk Dicuil in about 816 is the first known written.
The fold is really creative but I'd be afraid of an off by one error. I could reason it out, but being sure they meet where I think they do at the center and that I indeed can multiply by 50 would take more time than it should to convince myself.
I'd instead look at trying to collect/aggregate the ones, tens, & hundreds column. It turns out this is kind of a symmetric problem.
First, aggregate the singles column of this addition. You'll have 0-9, repeated 10 times. Add 1-9 and you get 45. Multiple by 10 since they're repeated for the aughts, the 10's, the 20's, &c. 450 is the total value of the first column of digits.
Second, aggregate the ten's column. The order is different but the values are the same. so it'll come to the same 450. 450 * 10 = 4500.
I really like the author's late conclusion on the many approaches to solving the problem:
> What I discovered when I tried this experiment is that it's really hard to do it the hard way. You may set out to plod dutifully through all the addition operations, but shortcuts present themselves even when you're not looking for them.
A lot of celebrity myths can be verified in 2022. Michael Jordan often recounted [0] that he was cut from his high school basketball team. Reporters found his high school coach who clarified that Michael was placed on junior varsity just like everyone else in his year[1].
[0] Here in his hall of fame enshrinement speech https://youtu.be/XLzBMGXfK4c?t=38 [1] An article about another article :/ but the links from here to the original are dead. https://bleacherreport.com/articles/1020151-michael-jordans-...