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Conceptual learning is fine, but you have to memorize some base cases. I don't think about 9 x 9. I just know it's 81. If you have to think about that every
by aneesh 19y ago
Conceptual learning is fine, but you have to memorize some base cases. I don't think about 9 x 9. I just know it's 81. If you have to think about that every time, you'll be so slow at doing anything. At the same time, learn multiplication too. You should know how to do 637 x 59 if you have to.
- Retric 19y agoIMO the way you learn how to do 637 * 59 is also important. I don't think this is faster but someone who does this: 637 x 59 = 637 * 60 - 637 = 637 * 60 - 637 = 36000 + 37 * 60 - 637 = 36000 + 40 * 60 - 637 - 3 * 60 = (36000 + 2400) - ( 637 + 180) = 38,400 - 817 = 38,000 - 420 + 3 = 37,000 + 580 + 3 = 37,583 IMO they are a lot closer to algebra than someone who does: 637 * 5 * 10 + 637 * 9 = (3000 + 150 + 35) * 10 + (5400 + 270 + 63) = 31850 + 5733 = 57,583 They also know it's around 38k at the second step.