Algebra and trig wasn't until secondary school for me ("year 7" we called it, school year beginning age 11), though I personally had a head start from having learned to read with the Commodore 64 user manual.
Well, if you're not willing (or we'll calibrated enough), I should get some old exam papers, see how well it grades against students. I wonder if there even are any downloadable pre-GCSE exams…
Edit: also, where might I find some old Polish example exams and marking schemes? ChatGPT is inherently multilingual, so I might as well.
This thread is no longer on my first page of comments, so I may forget to reply, but I've downloaded those and do intend to test it against those exams, and will put the write up here: https://github.com/BenWheatley/Studies-of-AI
Getting 3/4th of simple elementary school questions right indicates that someone is really bad at math. These are not difficult questions. I don't have time to come up with 20 exercises, but I can suggest a few that I think the AI may have trouble with. All of these are trivial single-variable linear equations that a smart elementary school student should have no problem with. (Note that the numbers are intentionally scrambled; this does not increase the difficulty of the problem):
1. Solve for x: 113(6x - 45) = 92x
2. Multiply 13.4a - 18b by 18b + 13.4a
3. Four girls bought bus tickets. Anne bought seventeen 20-minute tickets and paid $323. Marianne bought twenty-eight 75-minute tickets and paid $784. Alice bought nineteen 20-minute tickets and eight 75-minute tickets, and Alex bought seven thousand eighty five 20-minute tickets and ninety six 75-minute tickets. How much did Alex pay?
4. An old man walked fifty nine kilometres in four hours through a flat field. He drove a car to France for nine hours, and then proceeded to walk for eighteen hours through a flat field at the same pace. How many kilometres did the old man walk in France?
5. Alice bought seventy-nine pens and twenty-six notebooks. The arithmetic mean of the cost of these articles was $9.31. The sum of the cost of the notebooks was $112.762. How much did a pen cost?