How To Calculate Cube Roots In Your Head

Here's how you do cube roots in your head! Avoid looking like Education Secretary Nicky Morgan who was stumped when asked to do a cube root: https://www.youtube.com/watch?v=x8CV0dfQMdU Note: the starting number needs to be a perfect cube. So it's more of a magic trick: ask someone to cube a number and then you can deduce their original number quickly. Check out my book "The Best Mental Math Tricks" (rated 4.7/5 stars on 4 reviews) http://amzn.to/18maAdo Can you multiply 97 by 96 in your head? Or can you figure out the day of the week when you are given a date? This book is a collection of methods that will help you solve math problems in your head and make you look like a genius. "The Best Mental Math Tricks" (rated 4.7/5 stars on 4 reviews) http://amzn.to/18maAdo H/T Mashable http://mashable.com/2014/12/12/education-minister-maths-question/ Arthur Benjamin is a Professor at Harvey Mudd College and well-known for feats of mental calculation. He explains the cube root algorithm in this pdf https://www.math.hmc.edu/~benjamin/papers/Cubing.pdf This trick is really old--here's a newspaper article from 1913 that explains the trick! http://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SFC19130615.2.162.13.11 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can't always reply! Why are there comments before the video is published? Get early access and support the channel on Patreon https://www.patreon.com/mindyourdecisions If you buy from the links below I may receive a commission for sales. This has no effect on the price for you. Show your support! Get a mug, a t-shirt, and more at Teespring, the official site for Mind Your Decisions merchandise: https://teespring.com/stores/mind-your-decisions My Books Mind Your Decisions: Five Book Compilation https://amzn.to/2pbJ4wR A collection of 5 books: "The Joy of Game Theory" rated 4.1/5 stars on 44 reviews http://amzn.to/1uQvA20 "The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" rated 3.5/5 stars on 4 reviews http://amzn.to/1o3FaAg "40 Paradoxes in Logic, Probability, and Game Theory" rated 4.4/5 stars on 13 reviews http://amzn.to/1LOCI4U "The Best Mental Math Tricks" rated 4.7/5 stars on 8 reviews http://amzn.to/18maAdo "Multiply Numbers By Drawing Lines" rated 4.3/5 stars on 6 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 13 reviews http://amzn.to/1GhUUSH "Math Puzzles Volume 2" rated 4.5/5 stars on 6 reviews http://amzn.to/1NKbyCs "Math Puzzles Volume 3" rated 4.1/5 stars on 7 reviews http://amzn.to/1NKbGlp Connect with me My Blog: https://mindyourdecisions.com/blog/ Twitter: https://twitter.com/preshtalwalkar Newsletter (sent only for big news, like a new book release): http://eepurl.com/KvS0r 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.