[pryelluw]

My kid just learned by memorizing the results in order. Like: 8, 16, 24, 32, etc. If the problem is 5x8 then she knows its the fifth number in the sequence. Did not take her a lot of time to then learn the whole formula. Now that I think about it, this is like calculating results in a hash table for easy retrieval later.

We used this video (and channel) and it helped lots:

https://youtu.be/IjPjks1R6Ng

[charmonium]

when you get to 5x + x = 6x, you can't simply memorize a similar sequence. Knowing how the sequence is created is much more valuable than memorizing the sequence. You do loose some speed, but critical thinking is more important than speed, especially with the onset of cheap personal computers and calculators.