The teacher's meaning is clear and the kid should just answer what is being asked, not what is being said. So the kid is in the wrong. If you're smart enough to be this clever, just answer the question.
The teacher says "You are wrong, failed" when the kid is technically correct, instead of clarifying the intent of the question. So the teacher is in the wrong. "Clever, but you know what I meant" solves the problem. "You get an A in math and an F in interpreting language"
On the flip side, I had a cousin who had a question on a test: "What is the largest SI prefix" ... he answered "yotta" (which at the time was the largest)... And got it wrong. because the "correct" answer was "mega". Because that was the largest the class had learned about at the time, and the teacher was very inflexible on this; they acknowledged that yotta was the largest, but my cousin had learned about it outside of class, so it couldn't be an acceptable answer. The teacher couldn't possibly fathom marking "mega" right for students who had only context from the classroom and also marking "yotta" right for students who had done independent research. No, the question was IMPLIED to be "what is the largest SI prefix [that we have covered in class]" and anything else was wrong.
The teacher couldn’t possibly fathom marking “mega” right for students who had only context from the classroom and also marking “yotta” right for students who had done independent research.
That is child abuse. Literally. The way my teachers worked, presumably because they learned how to deal with the situation when actually studying pedagogics (a thing we require of teachers here) is to give an extra point because you want to encourage kids to figure things out on their own.
And this folks is why you don’t hire “math teachers” because he was a successful football coach. It took him way too long to realize this is why we don’t divide by zero, (more than a week, actually.)
That's decidedly unfun and headhurty for those of us less mathemstically inclined. Also so deep into the theoretical weeds that I'm not sure that "fact" applies..
As a software developer this is a 100%* correct operation.
*From a logical perspective in C-like pseudocode. In reality you may have to add a „;“, a line break or other line delimiters if someone from Stackoverflow reads this
...if that's too heady do note that if you have a heap of four marshmallows and a heap of five marshmallows then that's the same as having a heap of five marshmallows and a heap of four marshmallows. To have a heap of nine marshmallows, you first have to turn them into a single heap. That's reducing the number of heaps from two to one and that's a hand-wavy way to justify the term.
There really are few good math instructors out there. They tend to be those who have intuitions about the subject who can’t interact with people who weren’t born with them.