Controversial math problem. Why was 5x3 = 15 marked wrong?

Video Description

The internet went crazy over this problem...but there is more to the story than the media reported. References https://www.reddit.com/r/pics/comments/3pmyh3/teachers_logic_in_grading_math/ https://www.al.com/news/2015/11/what_is_5x3_heres_the_common_c.html https://www.today.com/parents/third-graders-math-assignment-reignites-debate-over-common-core-standards-t52971 https://www.salon.com/2015/11/28/youre_wrong_about_common_core_math_sorry_parents_but_it_makes_more_sense_than_you_think/ https://www.dailymail.co.uk/news/article-3291895/The-grade-math-question-puzzled-5-5-5-15-NOT-correct-answer.html https://matheducators.stackexchange.com/questions/9842/repeated-addition-standard-notation https://blogs.scientificamerican.com/roots-of-unity/teaching-the-controversy-is-5-3-five-3s-or-three-5s/ https://medium.com/i-math/why-5-x-3-5-5-5-was-marked-wrong-b34607a5b74c http://www.patheos.com/blogs/friendlyatheist/2015/10/21/why-would-a-math-teacher-punish-a-child-for-saying-5-x-3-15/ https://www.motherjones.com/politics/2014/09/common-core-education-reform-backlash-obamacare/ https://www.npr.org/2014/01/28/267488648/backlash-grows-against-common-core-education-standards https://corestandards.org/wp-content/uploads/2023/09/Math_Standards1.pdf https://en.wikipedia.org/wiki/Multiplication https://en.wikipedia.org/wiki/Multiplication_and_repeated_addition https://en.wikipedia.org/wiki/Common_Core Euler Elements of Algebra originally published 1765 https://www.google.com/books/edition/Elements_of_Algebra/vV1NAQAAMAAJ?hl=en&gbpv=1&pg=PA9&printsec=frontcover https://en.wikipedia.org/wiki/Leonhard_Euler Euclid Elements Book VII (around 300 BCE) http://aleph0.clarku.edu/~djoyce/elements/bookVII/defVII15.html cover https://en.wikipedia.org/wiki/Euclid%27s_Elements#/media/File:Title_page_of_Sir_Henry_Billingsley's_first_English_version_of_Euclid's_Elements,_1570_(560x900).jpg Multiplication and repeated addition https://profkeithdevlin.org/devlins-angle/2008-posts/#jun08 https://en.wikipedia.org/wiki/Multiplication_and_repeated_addition Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you purchase through these links, I may be compensated for purchases made on Amazon. As an Amazon Associate I earn from qualifying purchases. This does not affect the price you pay. If you purchase through these links, I may be compensated for purchases made on Amazon. As an Amazon Associate I earn from qualifying purchases. This does not affect the price you pay. Book ratings are from January 2023. My Books (worldwide links) https://mindyourdecisions.com/blog/my-books/#worldwide My Books (US links) Mind Your Decisions: Five Book Compilation https://amzn.to/2pbJ4wR A collection of 5 books: "The Joy of Game Theory" rated 4.3/5 stars on 290 reviews http://amzn.to/1uQvA20 "The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" rated 4.1/5 stars on 33 reviews http://amzn.to/1o3FaAg "40 Paradoxes in Logic, Probability, and Game Theory" rated 4.2/5 stars on 54 reviews http://amzn.to/1LOCI4U "The Best Mental Math Tricks" rated 4.3/5 stars on 116 reviews http://amzn.to/18maAdo "Multiply Numbers By Drawing Lines" rated 4.4/5 stars on 37 reviews http://amzn.to/XRm7M4 Mind Your Puzzles: Collection Of Volumes 1 To 3 https://amzn.to/2mMdrJr A collection of 3 books: "Math Puzzles Volume 1" rated 4.4/5 stars on 112 reviews http://amzn.to/1GhUUSH "Math Puzzles Volume 2" rated 4.2/5 stars on 33 reviews http://amzn.to/1NKbyCs "Math Puzzles Volume 3" rated 4.2/5 stars on 29 reviews http://amzn.to/1NKbGlp 2017 Shorty Awards Nominee. Mind Your Decisions was nominated in the STEM category (Science, Technology, Engineering, and Math) along with eventual winner Bill Nye; finalists Adam Savage, Dr. Sandra Lee, Simone Giertz, Tim Peake, Unbox Therapy; and other nominees Elon Musk, Gizmoslip, Hope Jahren, Life Noggin, and Nerdwriter. My Blog https://mindyourdecisions.com/blog/ Twitter https://twitter.com/preshtalwalkar Instagram https://www.instagram.com/preshtalwalkar/ Merch https://teespring.com/stores/mind-your-decisions Patreon https://www.patreon.com/mindyourdecisions Press https://mindyourdecisions.com/blog/press