Hey, in case you are still interested, here is a little explanation on the algorithm: https://koljapluemer.com/2023/09/23/arabic-numbers-sr.html

It's a pretty lazy version of intra-session Spaced Repetition, vaguely based on Pimsleur's original definition, with some extras to avoid boredom/frustration.

Give me a day or so for a writeup then I come back to you :)