

I think a lot of the backlash against rote memorization is the rote part. Without understanding what you’re memorizing—treating the times table as a list of sequences (times table for 2, and then 4, and then 5, etc), the mental load memorizing it becomes unbearably high.
In my case, I was lucky enough to have been made to understand what’s going on (4 groups of 8 items = 40) before being asked to memorize the times table. The visualization also helped me memorize, as well as some tricks (what’s 6×7? 6×6 = 36, right? add 6 to arrive at 42) that as I memorize more and more of the table, become less and less necessary.
If it’s a civilization that hasn’t yet had a writing system, a writing system.
However, I will teach them a (semi-)featural alphabet, kinda like if the Hangeul jamo were its own alphabet. It’d be fun how long the orthography will diverge from the spoken sounds, and how fossilized the orthography can be–and more interestingly, how they might evolve the writing system.
If it’s a civilization that already is using a writing system, emojis that they can use alongside their writing system. It’d be interesting to see if they’d eventually turn into ideograms for human feelings and thoughts.