| > is something like 68 x 68 I got to 4624 in 8 seconds on that now, and I haven't done significant amounts of mental math in over a decade. The 60x8 etc took a couple of seconds each but other than that it just happens automatically. A decade ago each of those would take a fraction of a second and it takes about the same time to calculate as to write it, I tend to calculate the numbers left to right instead of right to left as you are taught since you write it left to right, also more useful when calculating approximations since I just do what I normally do but stop earlier. > Not in a doubting way, I just have no idea how I could do it in 2 seconds Words are just slow. I never did math with words, so arithmetics is fast, and so is all the other things you learn in a math degree. I think word based processing in math is a big reason people have such a tough time with it, it really makes it much harder to think, like you are bogged down in a fog instead of up and free and agile with clear sight of everything. Maybe it was easier for people to get past this stage when calculators were less prevalent. Calculators lets people get away with keeping their arduous word based math instead of just internalizing the concepts. > What if you were to have to do something more difficult e.g. 3 digits multiplication or 4? When on tests I write down some intermediate values. I am not a human calculator, I am just fast at math reasoning and being relatively fast at arithmetic's comes for free from that. I did some physics tests without a calculator, you can approximate all those special functions using regular math logic you learn in high school. I did still ace the test, it isn't that hard once you have internalized it all. |