The cat is sleeping, purring in time with the hissing of the radiator.
My 9th grade students have at last begun to understand what it means to write a proof.
"Do you mean I could just write it out in words? Just explain why it's true?"
Yes! That is exactly what I mean. Or you could draw a diagram. Or you could sing.
"Oh, Lord, Oh Lord, It's a Beautiful Day..."
Every year I have a little crisis mentally thinking they will never understand the point of writing proofs, or what they really are. Somehow I forget that the dawn still comes.
Oct 21, 2026, 12:07 PM@futurebird Interesting to me. I don't recall ever trying to teach this, despite teaching logic and philosophy. Maybe I just assumed they knew.
Oct 21, 2026, 12:09 PM@futurebird I think I got the point some time in college, writing proofs for some very simple CS things, like a simple algorithm for checking for balanced parentheses. I'm sort of susceptible to the thought "why should I trust my feeling that I know this is true", and responsive to the simplicity and provability of a formal proof system, like first order logic.
@adardis
It's usually taught in highschool geometry.
I don't recall either being given the option to sing the proof.
@futurebird 's lessons seem quite interesting !
(I hope the classroom is soundproofed, though - poor neighbours !)
A very old nonverbal proof you undoubtedly know.
@futurebird That’s wonderful
@futurebird I'm still kinda pissed at my high school sophomore geometry teacher who tried to take points off my test because my proof was different from hers and didn't bother to actually check my work.
@futurebird Way back when I was teaching basic electronic logic I used to get the kids to write a simple statement of how their circuit should work highlighting AND, OR and NOT If you can write it clearly, making the circuit with logic gates is simple.
But then I realised the kids couldn't think or write logically...
oh they can!
every human has an intrinsic understanding of logic but often it is only applied to subjects or objectives they:
* know well
* feel ownership over
I’ve had students who are failing at logic rattle off logical interpretations of the school rules on how much homework I can assign and on which days that would make the hair on the head of a Harvard law professor lay flat.
it’s there it’s just not connected to the rest of their model of the world
@futurebird @pthane I had a very good math teacher in primary school. I think I understood logic when he explained that the statement "If the moon is a green cheese, then I can eat it" is a TRUE statement 😁😅
@jakobtougaard @futurebird @pthane if there are other universes, somewhere out there is another universe in which the moon is made of green cheese, and many children have gotten into very, very bad trouble for eating very difficult to replace moon rocks.
"Furthermore, since there was a NYC recognized religious holiday this weekend, you cannot mark the homework late for at least one additional day--"
"Do you even celebrate Diwali?"
"Irrelevant!"
"ok."
I love kids like that.