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#pemdas#orderofoperations#parsing

PEMDAS is wrong

The How and Why of Mathematics

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  • An opinion. It argues one side of a question engineers disagree on.

Beginner. No background in the topic needed.

505K views8 years ago1 recommendation

Computer scienceProgramming languagesMath for programmersLanguage design and type systems

An explanation of why the standard PEMDAS order of operations is ambiguous and how mathematicians actually interpret implicit multiplication.

When it comes to order of operations (PEMDAS, BODMAS, BEDMAS, BIDMAS), who are you going to believe: your primary school teacher, or Richard Feynman? Applying PEMDAS to the viral maths puzzle "6/2(1+2) = ?" gives the answer 9, as explained in videos by MindYourDecisions and others, but is that the whole story... I'm an online maths tutor. Go to thawom.com/tutoring to find out more. You can also follow me on twitter at twitter.com/thawom0 References: Abstract Algebra- The Basic Graduate Year by Robert B. Ash faculty.math.illinois.edu/~r-ash/Algebra/SolutionsChap1-5.pd… p2 The Feynman Lectures on Physics Vol. I Ch. 6: Probability feynmanlectures.caltech.edu/I_06.html Basics of Mechanical Engineering by Paul D. Ronney ronney.usc.edu/ame101/ame101-lecturenotes.pdf p7 (page 15 of the pdf) Oliver Knill - Ambiguous PEMDAS math.harvard.edu/~knill/pedagogy/ambiguity/index.html AMS Guide for Reviewers May 2000 web.archive.org/web/20000815202937/http://www.ams.org/author… APS Physical Review Style and Notation Guide cdn.journals.aps.org/files/styleguide-pr.pdf p21

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What people say. Recommended to explain the parsing and precedence issues of implicit multiplication in programming language design.

u/cxzukin r/ProgrammingLanguages • Recommends

On “Implicit multiplication as syntactic sugar in a CoffeeScript dialect for teaching math”

Hi Koff, As already mentioned. Parsing does become harder with this syntax (juxtaposition). There is also a semantic issue. Multiplication by juxtaposition has a higher precedence than normal multiplication. `1/2x != 1/2 * x.` These two videos are good on explaining PEJMDAS PEMDAS is wrong The Problem with PEMDAS: Why Calculators Disagree M ✌️