Like it is just as primitive as makes intuitive sense in a way similar to division. I feel like teaching 4th graders the modulo function would complement learning division extremely well, as it helps make the idea of remainders and such concrete.
But first time I learned about modulo was comp sci in 11th grade. Calculators have five big buttons– +, -, x, ÷, = –but no modulo. PEMDAS (even excusing its flaws) includes no mention of it, and I've never, in any math class, plotted the graph of X%3. I feel like learning it a younger age makes using it more second-nature and gives a greater familiarity with the way numbers work. It's a good conceptual tool. In fact, why don't we teach the floor function too? It makes sense especially when considering things like time and its weird base 24-60-60-10 system
So why is it so obscure? Is it just not that applicable (I mean, I can think of lots of examples where it is…) Is it just one of those things that hasn't occurred to anyone?
Really, my question is not even about the practicality or the benefits. It just seems like a very basic and straightforward function that has simply been ignored.
Note: Some responses have noted that my use of the word modulo is questionable. Sorry about that. If it's unclear, by "modulo", I mean "remainder", which I had previously thought was a synonym of the aforementioned word.