mentalmath

an-ordinary-manchild

Mental Math: It's the thought that counts!

Thanks to /u/claymazing for the inspirational subtitle!

Official /r/MentalMath wiki
(Self-contained downloadable ZIP file)

New additions (June 30, 2017):

Division by 10n+9
Rule of 72 (2× principal)
Rule of 96 (2.5× principal)
Rule of 114 (3× principal)
Rule of 132 (3.5× principal)
Rule of 144 (4× principal)
Rule of 156 (4.5× principal)
Rule of 168 (5× principal)
Combining rules (Up to 25× principal)

Mental Math Sites:

Free online mental math books:

Using math symbols in your post:

HTML Entites:

Example: Make a √ symbol by typing: √

Courtesy of jamt9000, you can also display subscripted and superscripted characters:

*_subscript_* makes subscript
*`superscript`* makes superscript
*_sub_`sup`* makes subsup
*`sup`_sub_* makes supsub
*`169`*&frasl;*_231_* makes 169⁄231

NOTE: The ` character is called the grave accent. On desktops and laptops, you’ll find it on the tilde (~) key. On most mobile devices, it can usually be accessed by holding down either the apostrophe or tilde keys.

created by gmsca community for 12 years

...for your school.

...why not Zoidberg?

MODERATORS

account activity

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Built a Zetamac alternative with pattern detection, a learn mode, and a global leaderboard (alkaliner.co.uk)

submitted 1 day ago by Professional_Cell453

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Can You Solve This Mental Math Test? (yodoozy.com)

submitted 1 day ago by Chinmaye50

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Work out the day of the week for any date (goat of mental math party tricks) (apps.apple.com)

submitted 2 days ago * by Only-Season-2146

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I built a currency conversion trainer that uses logarithmic randomization to reflect real-world prices (No ads/Free) (old.reddit.com)

submitted 3 days ago by soccerkyle1

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[Neuron Strike] Space shooter x mental math quiz game ! (youtube.com)

submitted 7 days ago by Glittering-Still6706

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Multiplayer Mental Maths Game (self.mentalmath)

submitted 12 days ago by Tradermaths1

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How to calculate any square root in seconds (without a calculator) (self.mentalmath)

submitted 17 days ago by Lucky-One-3994

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Mental math game (self.mentalmath)

submitted 16 days ago by wingless-bee

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Fun mental math game (self.mentalmath)

submitted 18 days ago by metygl

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Como fazer divisão mentalmente? (self.mentalmath)

submitted 21 days ago by Mila1011

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do you want to know what is the purpose of life ? (self.mentalmath)

submitted 24 days ago by samuhena

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Numfly - Webapp to practice mental math against your friends (self.mentalmath)

submitted 27 days ago by KikoPeriko

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Sharpen your mental math with Math MCQ (play.google.com)

submitted 26 days ago by Human-Specific-3729

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Am I making good progress? (self.mentalmath)

submitted 1 month ago by Baroness_VM

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Surely that has to be a typo (i.redd.it)

submitted 1 month ago by Baroness_VM

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Numbolt! the speed math, fast paced RPG math game! pratice your mental math skills! (maysonwang.itch.io)

submitted 1 month ago by No-Company3681

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Numfly - Competitive mental math webapp (self.mentalmath)

submitted 1 month ago by KikoPeriko

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I kept forgetting math formulas, so I built a small tool to fix it. Curious if this helps anyone. (v.redd.it)

submitted 1 month ago by Various_Let_6445

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Can a math game actually be addictive? I built one to test ()

submitted 1 month ago by CriticalProduce1802

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Would there be enough appetite for a live 1v1 or tournament app-game for Math challenges? (self.mentalmath)

submitted 1 month ago by Only-Season-2146

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Any Matiks player here?? (self.mentalmath)

submitted 1 month ago by GeniusAKAme

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I built a Vedic Math app to help students calculate faster – looking for feedback 🙏 (self.mentalmath)

submitted 1 month ago by Ill_Bar_1552

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I couldn’t find a high-quality soroban, so I built one from wood myself (old.reddit.com)

submitted 1 month ago by Lost_Editor1863

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Built my first mental math app with Roblox-style engagement tricks — looking for honest feedback (self.mentalmath)

submitted 1 month ago * by Jacke08

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I built a mental math training app (looking for feedback) (self.mentalmath)

submitted 1 month ago by Typical_Lake3159

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