#mental-math — Public Fediverse posts

@2ndStar

Nur so mal aus Neugier gefragt.

Sind Apps, die spielerisch zum Rechnen, motivieren ein Thema in der Schule?

Ich hab früher PraktikantInnen öfters mal
#RUTMath und #MentalMath empfohlen

Bihar Student Secures Top Honours at National Abacus Championship.

https://aliyesha.com/sub/articles/news/display/bh_samarth_top_honour_abacus

#NationalAbacusChampionship #SamarthSinha #PatnaPride #BiharTalent #MentalMath #AbacusSkills #EducationExcellence #MathGenius #News

Enjoy tracker free reading with us. #privacy #privacymatters

New blog post: Someone in a video call mentioned they just moved to Bali. Another friend lives in Osaka. They asked half-jokingly which is closer to us in Hanoi. I said Osaka before they had Maps open.

Didn't fully clock until later that I've had a system for this the whole time, accidental trigonometry moment lol :meowBox:

https://jarema.me/blog/2026/05/timezone-distance/

#blog #geography #mentalmath #100DaysToOffload (6/100)

Math Magic: How To Master Everyday Math Problems "Math Magic makes math what you may never have imagined it to be: easy and fun!" Sale: $18.99 to $1.99 by Scott Flansburg & Victoria Hay Rating: 4.6/5 (333 Reviews) #Math #MentalMath #Arithmetic #Education #Books #Learning #BookSky

Math Magic: How To Master Ever...

Strengthen mental maths daily.
#MentalMath #Addition #MathQuiz #Education #GK #QuizTime

Một nhà phát triển đã ra mắt MonkeyMac, trò chơi web kết hợp thử thách gõ phím tốc độ (như MonkeyType) và luyện tính nhẩm (như ZetaMac). Trò chơi miễn phí, không cần đăng ký (tùy chọn theo dõi tiến độ), giúp cải thiện tốc độ tính toán và phản xạ.
#Game #MathGame #SpeedTyping #MentalMath #WebGame #TròChơi #ToánHọc #TínhNhẩm #GõPhímNhanh

https://www.reddit.com/r/programming/comments/1o3d9mx/i_combined_zetamac_and_monkeytype_into_the_best/

Một game mới kết hợp ZetaMac & MonkeyType đã ra mắt! 🎮 Thử thách khả năng tính nhẩm siêu tốc với giao diện gõ phím quen thuộc. Chơi miễn phí trên trình duyệt, không cần đăng ký (có thể tạo tài khoản theo dõi tiến độ). Hoàn hảo cho ai thích toán và tốc độ!
#Game #Math #MentalMath #Typing #BrowserGame #FreeGame #TròChơi #ToánHọc #TínhNhẩm #GõPhím

https://www.reddit.com/r/programming/comments/1o3d9mx/i_combined_zetamac_and_monkeytype_into_the_best/

Chơi game rèn luyện trí não MIỄN PHÍ! 🧠✨
Game Mental Math (trị giá $17.99) đang miễn phí hoàn toàn phiên bản cao cấp trong 48 GIỜ trên App Store.
Không quảng cáo, không đăng ký. Tải ngay để rèn luyện tư duy toán học của bạn!
#MentalMath #FreeApp #GameMienPhi #LuyenTriNao #AppStore #iOSGame

https://www.reddit.com/r/SideProject/comments/1o08gu4/sharpen_your_mind_mental_math_game_free_for_48/

For Americans Only: Estimating Celsius and Other Mental Metrics - I know many computer languages, but I’ve struggled all my life to learn a second h... - https://hackaday.com/2025/08/14/for-americans-only-estimating-celsius-and-other-mental-metrics/ #hackadaycolumns #mentalmath #metric #rants

For Americans Only: Estimating Celsius and Other Mental Metrics https://hackaday.com/2025/08/14/for-americans-only-estimating-celsius-and-other-mental-metrics/ #HackadayColumns #mentalmath #metric #Rants

Today's Poll....

What is the value of this? 8 + 2 × (5² − 3) ÷ 2

#MentalMath #STEMFun #PuzzleTime #TuxAcademy #MathIsFun #Poll #Datascience #AI #Tech

"Word riddles at the public library" https://www.youtube.com/watch?v=EvSxhyJhfM8

Fun questions to ask nieces, nephews, grandkids -- and other nice people -- at Thanksgiving -- or any other time of year. Encourage people to invent their own original questions.

See also - "Coin questions at the library" https://www.youtube.com/watch?v=M11WT3H_DqU suitable from kindergarten all the way up to high school.

#mtbos #edutwitter #riddles #informaleducation #mentalmath #puzzles

Game: Target Number (or 24)

[Photo by stevendepolo via Flickr (CC BY 2.0).]

Math concepts: addition, subtraction, multiplication, division, powers and roots, factorial, mental math, multi-step thinking
Number of players: any number
Equipment: one deck of playing cards (face cards and jokers removed), pencils and scratch paper, timer (optional)

Set Up

All players must agree on a Target Number for the game. Try to choose a number that has several factors, which means there will be a variety of ways to make it. Traditionally, I start my math club students with a target of 24.

Shuffle the deck, and deal four cards face down to each player. (For larger target numbers, such as 48 or 100, deal five or six cards to each player.) The players must leave the cards face down until everyone is ready. Set the remainder of the deck to one side.

How to Play

• At a signal, all players pick up their hands and look at the cards. Each player tries to combine all four numbers in his hand to make the target number.
• Players may add, subtract, multiply, or divide the numbers in any order, but they may not put two cards together to make a two-digit number. With older students, allow using one card as an exponent on another. Factorials and the square root function may also help to spice up the game.
• Each card may be used only once in the calculation.

For example, if the target number was 24, and you were dealt a 4, 3, 7, and 9, you might try:
(9 × 3) – 7 + 4 = 24
or
(9 – 7) × 3 × 4 = 24
but not
(9 ÷ 3) × 4 = 24,
which ignores the 7 card.

• There is an element of chance to the deal. Some hands will not make the target number, no matter how you combine them.
• If after a few minutes, all players seem stumped, the dealer should give each player one more card. Then the players may use all five cards in their hands or choose any combination of four cards.
• On rare occasions, the dealer may have to deal another round of extra cards before any player can hit the target.

Endgame

When you figure out a way to make the target number, lay your cards face up on the table. Explain your calculation so the other players can check it.

The first player to make the target number, using at least four cards in legal arithmetic calculations, is the winner of that hand. Play several hands, scoring one point per hand, and the first player to score six point wins the game.

Variations

Target Race: To eliminate the element of chance, deal four cards face up in the middle of the table. All players use these cards, and whoever is the first to figure out how to calculate the target number wins that hand.

Target Number with Variables: For a faster-paced game, include the face cards in your deck, and let them work as variables. A face card in your hand may take any value that a number card might have, from 1 to 10.

Target Dice: Instead of cards, throw five dice on the table. All players try to combine the numbers showing on the dice to make the target number.

Timed Target Number: Give each player a piece of paper and a pencil or pen. Set the timer for an agreed-upon time, perhaps 10 or 15 minutes. Deal 8 cards face up on the table, and start the timer. Each player writes on a piece of paper all the ways he can combine any of these numbers to make the target number. Each card may be used only once in each calculation, but it may be reused in as many different calculations as you can think of. For example, if the target is 24, and a player wants to use the equation 3 × (4 + 4) = 24, there must be a 3 and two 4s on the table. Whoever comes up with the most (valid) ways to calculate the target number wins.

Target Solitaire: Play a solitaire game by dealing 8 cards face up and challenging yourself to find all the ways they can be combined to make your target number.

Comments

Peggy Kaye (Games for Math) suggests a game like my Timed Target Number variation, but for younger students. She deals out only 5 cards and sets the target number as 10.

I have also enjoyed the commercial version of Target Number, called the 24 Game, which uses special playing cards invented by Robert Sun. The game comes in a wide range of levels, allowing students to practice topics from simple addition and subtraction to fractions, decimals, and even algebra.

 
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