The only way to get to automaticity is to drill, drill, and more drill. I get that about learning kanji and it applies to mathematics also in the grammar school levels. In Japan, I got to see a soraban school at work and it is drill and more drill but the kids knew how to use mental soraban by the time they were finished.
Yep, automaticity!

Rothbardian_fanatic

I think you summed this up in one word: automaticity. We got to bolster their automaticity so that they don’t expend their cognitive energy on thinking how to do