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>It's little things, like going through how the quadratic formula is derived instead of just telling someone to learn it by rote. Explaining differentiation wit

>It's little things, like going through how the quadratic formula is derived instead of just telling someone to learn it by rote. Explaining differentiation with a bit of the logic behind it instead of just teaching rules. Once you get in the mindset of deriving equations, rote memorization becomes insanely difficult, at least in my opinion. During my last year as an undergrad majoring in physics I got a 4.0 in quantum mechanics, but very nearly failed introductory chemistry (which I was taking to fill a science distribution requirement at a liberal arts college), despite many of the chemistry concepts just being edge cases of applied quantum mechanics. There was also the very embarrassing case of being called to the blackboard to complete a problem in an elective course on number theory only to draw a blank on what 9 times 7 was. I understood the solution to the problem itself, but when the professor started giving me hints I had to admit in front of the whole class that my issue wasn't with the number theory proof -- it was with the multiplication table we learn as children.

dingo_bat 11y ago
>what 9 times 7 was Is there a reason you didn't whip out a calculator and do it there? Although I must say that I remember everything till 20x20 :P
- fluxquanta 11y ago
  I was standing at the blackboard in front of the class. I've always been flaky on multiplication tables for some reason, and doing arithmetic in my head isn't my strongest suit. That said I excelled in math throughout high school and college. It just goes to show that elementary math really has no bearing on the type of mindset one may have for "more complex", logic based math and computation. Trust me -- since that experience of being humiliated in front of the best students in the math department at my college, I haven't forgotten what 9 times 7 is.
  - j2kun 11y ago
    Once in a graduate abstract algebra class (without being prompted) I interrupted the professor's lecture to remark that he had skipped the prime "15" in a list of primes he wrote on the board.
JadeNB 11y ago
> There was also the very embarrassing case of being called to the blackboard to complete a problem in an elective course on number theory only to draw a blank on what 9 times 7 was. If it's any consolation, the great mathematician Alexander Grothendieck (https://en.wikipedia.org/wiki/Alexander_Grothendieck https://en.wikipedia.org/wiki/Alexander_Grothendieck), when asked to supply a prime number (at some point in a lecture)—and being puzzled by the idea of actually naming a specific prime number—famously thought for a while before suggesting 57. (https://en.wikipedia.org/wiki/57_%28number%29#In_mathematics https://en.wikipedia.org/wiki/57_%28number%29#In_mathematics)
jimbokun 11y ago
10 - 1 = 9 9 * 7 = (10 - 1) * 7 = 70 - 7 = 63 I often do little calculations like this when I forget multiplication table entries.
- fluxquanta 11y ago
  As do I, but the pressure of the situation didn't help, especially when the natural assumption of the professor/rest of the class was that I didn't understand the much more "complicated" aspect of the proof and not something most people take for granted as just "known" from elementary school.
qubitcoder 11y ago
You can also use your 10 fingers to instantly multiply by 9s. Spread out your fingers. Number them from 1 to 10, left to right (i.e. left-hand little finger = 1). For 9 * 7, simply curl finger 7 downwards. Now you have 6 fingers on the left, and 3 fingers on the right. Voila, 63. :-)

dingo_bat 11y ago

>what 9 times 7 was Is there a reason you didn't whip out a calculator and do it there? Although I must say that I remember everything till 20x20 :P

fluxquanta 11y ago
I was standing at the blackboard in front of the class. I've always been flaky on multiplication tables for some reason, and doing arithmetic in my head isn't my strongest suit. That said I excelled in math throughout high school and college. It just goes to show that elementary math really has no bearing on the type of mindset one may have for "more complex", logic based math and computation. Trust me -- since that experience of being humiliated in front of the best students in the math department at my college, I haven't forgotten what 9 times 7 is.
- j2kun 11y ago
  Once in a graduate abstract algebra class (without being prompted) I interrupted the professor's lecture to remark that he had skipped the prime "15" in a list of primes he wrote on the board.

JadeNB 11y ago

> There was also the very embarrassing case of being called to the blackboard to complete a problem in an elective course on number theory only to draw a blank on what 9 times 7 was. If it's any consolation, the great mathematician Alexander Grothendieck (https://en.wikipedia.org/wiki/Alexander_Grothendieck https://en.wikipedia.org/wiki/Alexander_Grothendieck), when asked to supply a prime number (at some point in a lecture)—and being puzzled by the idea of actually naming a specific prime number—famously thought for a while before suggesting 57. (https://en.wikipedia.org/wiki/57_%28number%29#In_mathematics https://en.wikipedia.org/wiki/57_%28number%29#In_mathematics)

jimbokun 11y ago

10 - 1 = 9 9 * 7 = (10 - 1) * 7 = 70 - 7 = 63 I often do little calculations like this when I forget multiplication table entries.

fluxquanta 11y ago
As do I, but the pressure of the situation didn't help, especially when the natural assumption of the professor/rest of the class was that I didn't understand the much more "complicated" aspect of the proof and not something most people take for granted as just "known" from elementary school.

qubitcoder 11y ago

You can also use your 10 fingers to instantly multiply by 9s. Spread out your fingers. Number them from 1 to 10, left to right (i.e. left-hand little finger = 1). For 9 * 7, simply curl finger 7 downwards. Now you have 6 fingers on the left, and 3 fingers on the right. Voila, 63. :-)