I don't know if this is relevant but I found it fascinating.

I saw a documentary, long ago, about primary school students in China with abacuses. They used the abacuses for mathematics, and they were blindingly fast with them.

And then they stopped using the physical abacuses and just sort of mimed the actions with their hands. And then, later, they stopped using their hands.

So, as far as I could see, they were training themselves to do maths via their muscle memory, and it seemed terrifyingly effective.