a) The value of knowing your first 100 squares has been discussed pretty thoroughly and the high percentage of coverage that can be had through knowing simple differences of squares and the binomial theorem gives a large coverage of the space for little investment.
b) Advancing multiplication tables up to 20 or so has also been quite productive in terms of raw speed. (I will continue with this mostly as a matter of becoming more familiar through practice in calculation).
c) Practicing basic addition and substraction 1/2/3 digit has also been helping. Both getting very comfortable with carries AND learning how to use complements to avoid carries.
d) Learning how to “read” a multiplication as opposed to calculating it. (Somewhere between calculation and memorization)
I’m looking for my next bit of rote memorization to help me along the way…
Has anyone tried focusing on learning the Prime factors and their multiplicands to 10,000 /1000/100 ??? and using them as pivot points for mental calculation? It seem like factoring via primes should provide a strong alternative method for calculation but I’ve never found it recommended anywhere. If you have how did you go about it? Was it productive? Fun? Simply another entertaining way of thinking about calculation while you waited for your brain to catch up with your ego?
Any other suggestions for calculating fun? I don’t want to spread myself to thin but I don’t want to burn out on a single set of drills either.