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Mental arithmetic

Anonymous Thu 20 Feb 17:51:07 2020 No.11402469 View Reply Original Report

Quoted By: >>11402512

Why am i unable to do basic arithmetic in my head yet I got A's in calculus, linear algebra and differential equations in college

Anonymous

Anonymous Thu 20 Feb 2020 17:58:09 No.11402482 Report

Quoted By: >>11402528

Pick up a book on mental arithmetic if you want to learn it. There are actually a number of interesting tricks to learn.

For example, using the identity x^2 - y^2 = (x-y)(x+y) to calculate products.

e.g. 47*53 = (50-3)(50+3) = 2500 - 9 = 2491

to make a contrived example.

Anonymous

Anonymous Thu 20 Feb 2020 18:10:51 No.11402512 Report

Quoted By: >>11402539

>>11402469
It's a matter of practice. For multiplication, you can just grab some basic combinatorics book and go ham on the problems. Just pen and paper, no calculator. Double check your results and use multiple approaches until you reach the same results.

Anonymous

Anonymous Thu 20 Feb 2020 18:16:06 No.11402528 Report

Quoted By:

>>11402482
I'm studying an old textbook right now. Goes in to associative and commutative properties for simple algebraic addition and subtraction. I can't even get the full answers the book wants (it goes in depth with the answers) but it is usefull nonetheless. Much better than some stupid stuff a modern book would try to explain. If you want to do advanced math start out with advanced basics. Makes cents.

Anonymous

Anonymous Thu 20 Feb 2020 18:17:55 No.11402539 Report

Quoted By:

>>11402512
You can go over times tables and simple algebra in your head as well. I've often had problems with math terminoligy. Would be nice to have a flashcard of just terminoligy.

Anonymous

Anonymous Fri 21 Feb 2020 02:24:25 No.11403805 Report

Quoted By:

no real job nowadays requires you to be competent at mental, or even pen-and-paper arithmetic. unless you're a clerk or a shopkeeper or something. why even bother? save those neuronal connections to solve actual, interesting problems.

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