Oh my God it's sooo incredibly dumb and I hate myself for not getting it
Glad you enjoyed it despite the frustration! I'm sure you can handle the rest though, the two puzzles at the start are easily the hardest part (which comes as a result of the fact that the original version of the game was made as a school project, and the graders needed to see the more complex rooms early in the game, haha)
(moving my other comment to the end of the thread):
There's a few other ways to get the solution to that puzzle! (Alternatively, the math-y puzzle that's the other direction from the entrance leads to the same location!)
In total, there are seven distinct correct solutions to get past the puzzles, though I'm not sure if the walkthrough has all of them listed. (If you haven't tried guessing incorrectly in both of them a few times, I suggest trying that, as they provide hints!)
You can (encoded with rot13.com, paste this there to see the solutions):
- Uvtuyvtug gur "vaivfvoyr vax" ng gur obggbz bs gur cntr gung gur punenpgre uvagf ng, nyybjvat lbh gb ernq gur anzr. (Uvggvat PGEY-N vf na rnfl jnl gb svaq vg, ohg lbhe zbhfr jbexf gbb!)
- Erpbtavmr gur "Ehzcyrfgvygfxva" snvel gnyr naq chg gbtrgure gung lbh arrq gb glcr uvf anzr onpxjneqf, yvxr va gur tnzr Xvat'f Dhrfg.
- Erpbtavmr gur Xvat'f Dhrfg ersrerapr, naq ragre gur zvfcryyrq anzr hfrq va gung tnzr.
- Gur cerivbhf gjb zrgubqf nyfb jbex vs lbh hfr n "onpxjneqf nycunorg" vafgrnq bs syvccvat gur jbeq, jvgu n=m, o=l, p=k, rgp.
- Fbyir gur zngu chmmyr, ol rvgure hfvat zbqhyb be qenjvat vg bhg ba cncre.
- Gel gur zngu chmmyr n srj gvzrf. Lbhe punenpgre jvyy oehgr sbepr gur fbyhgvba nsgre lbh trg vg jebat n pbhcyr gvzrf.