Wikimedia
Wikipedia: Additive Inverse
What is additive inverse? It means "opposite." Find out more about this concept in this detailed definition with examples and links to related terms.
Math Is Fun
Math Is Fun: Definition of Abacus
You can use an abacus to count, add, subtract, multiply and more. Try this interactive abacus and see if you can make the numbers. Choose "here's more" for some clues. Good luck!
Beacon Learning Center
Beacon Learning Center: Cameron's Trip
Students solve multiplication and division real-world problems in this interactive web lesson.
The Math League
The Math League: Decimals, Whole Numbers and Exponents
This tutorial has definitions and examples of decimals, whole numbers, and exponents. In addition, a variety of topics are covered, such as comparing, multiplying and subtracting.
Beacon Learning Center
Beacon Learning Center: Arrange a Party
Students use problem solving skills to calculate the range for a set of data and plan a party for friends.
abcteach
Abcteach: Number Puzzles
[Free Registration/Login Required] Solve the number puzzles as you practice basic addition skills and improve your number sense. The site has challenging activities with varying levels of difficulty.
![De Paul University: Center for Urban Education: Changing Transportation Routes [Pdf] Unit Plan](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "De Paul University: Center for Urban Education: Changing Transportation Routes [Pdf] Unit Plan")
Polk Brothers Foundation Center for Urban Education at DePaul University
De Paul University: Center for Urban Education: Changing Transportation Routes [Pdf]
"Changing Transportation Routes" is a one page, fictional, reading passage about how the problem of public transportation could be solved through the process of surveying the community, developing a workable solution, and presenting it...
Curated OER
Google for Education: Children and Technology: Full Development Cycle
Experience what it's like to work in the field of technology, and take on something never done before. Brainstorm, prototype, plan, implement, work in a team, coordinate between teams, learn from failures or enjoy a success.
PBS
Tower Power Returns: Engineering Is Elementary
"In this activity from Engineering is Elementary, students design, build, and test a tower that can hold up a stuffed animal. The activity is useful for introducing components of Engineering Design (ETS) from the Next Generation Science...
Maths Challenge
Maths challenge.net: Problem Solving Database
Need some challenging problem-solving work for your students in the following areas: Discrete, Geometry, Numbers, and Code Breaking? This is the place for an enormous database of problems aimed at high school age students. They are...
Thomas Jefferson National Accelerator Facility
Jefferson Lab: Place Value Game
This interactive math game lets you create the largest number possible as the computer gives you numbers.
TED Talks
Ted: Ted Ed: Evolution's Gift of Play, From Bonobo Apes to Humans
Learn about our similarity to apes, and how they solve their problems so peacefully at times but humans, the more "advanced" species, can behave so primitively. [7:02]
TED Talks
Ted: Ted Ed: Can You Solve the Three Gods Riddle?
You and your team have crash-landed on an ancient planet. Can you appease the three alien overlords who rule it and get your team safely home? Created by logician Raymond Smullyan, and popularized by his colleague George Boolos, this...
TED Talks
Ted: Ted Ed: Can You Solve the Counterfeit Coin Riddle?
You're the realm's greatest mathematician, but ever since you criticized the Emperor's tax laws, you've been locked in the dungeon. Luckily for you, one of the Emperor's governors has been convicted of paying his taxes with a counterfeit...
TED Talks
Ted: Ted Ed: How High Can You Count on Your Fingers? Spoiler:much Higher Than 10
How high can you count on your fingers? It seems like a question with an obvious answer. After all, most of us have ten fingers- or to be more precise, eight fingers and two thumbs. This gives us a total of ten digits on our two hands,...
TED Talks
Ted: Ted Ed: Can You Solve the Airplane Riddle?
Professor Fukano, the famous scientist, has embarked on a new challenge - piloting around the world in a plane of his own design. There's just one problem: there's not enough fuel to complete the journey. Luckily, there are two other...
TED Talks
Ted: Ted Ed: Can You Solve the River Crossing Riddle?
As a wildfire rages through the grasslands, three lions and three wildebeest flee for their lives. To escape the inferno, they must cross over to the left bank of a crocodile-infested river. Can you help them figure out how to get across...
TED Talks
Ted: Ted Ed: Can You Solve the Prisoner Boxes Riddle?
Your favorite band is great at playing music but not so great at being organized. They keep misplacing their instrucments on tour.
TED Talks
Ted: Ted Ed: Can You Solve the Passcode Riddle?
In a dystopian world, your resistance group is humanity's last hope. Unfortunately, you've all been captured by the tyrannical rulers and brought to the ancient coliseum for their deadly entertainment. Will you be able to solve the...
TED Talks
Ted: Ted Ed: Can You Solve the Control Room Riddle?
As your country's top spy, you must infiltrate the headquarters of the evil syndicate, find the secret control panel, and deactivate their death ray. But your reconnaissance team is spotty, and you have only limited information about the...
TED Talks
Ted: Ted Ed: Should You Trust Unanimous Decisions?
Imagine a police lineup where ten witnesses are asked to identify a bank robber they glimpsed fleeing the scene. If six of them pick the same person, there's a good chance that's the culprit. And if all ten do, you might think the case...
TED Talks
Ted: Ted Ed: Can You Solve the Locker Riddle?
Your rich, eccentric uncle just passed away, and you and your 99 nasty relatives have been invited to the reading of his will. He wanted to leave all of his money to you, but he knew that if he did, your relatives would pester you...
TED Talks
Ted: Ted Ed: Can You Solve the Frog Riddle?
You're stranded in a rainforest, and you've eaten a poisonous mushroom. To save your life, you need an antidote excreted by a certain species of frog. Unfortunately, only the female frog produces the antidote. The male and female look...
TED Talks
Ted: Ted Ed: Can You Solve This?
In this video, Veritasium asks people to try and figure out the rules of a pattern presented. This video teaches us about the scientific method and how our preconceived notions can affect how we discover new information. [4:43]