To commemorate the 25th anniversary of the explosion of the Challenger, PBS provides an article that describes the repercussions of the disaster.

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...

Students will build a water drop maze using no-cost materials and see if they can make it to the end without their drop of water falling off or falling in.

A brief survey of the beginning of the Cold War and the challenges that faced the United States in confronting communist totalitarianism.

Find the distance between points, graph points, and interpret data on coordinate planes to solve word problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Try some coordinate plane word problems focusing on quadrant 1. Miss the problem, and Kahn offers some tutorials for help.

Round decimals using number lines. Select numbers that round to a given value. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Just like the Montgomery Bus Boycott, the first sit-in at a Woolworth's lunch counter was the beginning of a nonviolent movement to challenge "white only" laws. Read about how the sit-in movement spread across the South. See how...

Support healthy eating by using these resources in the classroom. The Healthy Lunchtime Challenge was a nationwide recipe contest for kids ages 8-12 that promotes cooking and healthy eating. Winners attended a "State Dinner" at the White...

Learn basic keyboarding with this interactive keyboard. The focus is on identifying letter positions on the keyboard. Responses are checked immediately.

Research and report on two pressing environmental concerns in Africa: the scarcity of clean water and the desertification of farmland. Respond to these issues through activities involving art, drama and journalism.

This is a site that describes African women moving away form the traditional roles in society and shaping the political and social culture in all areas of Africa.

This tutorial makes the memorization of metric prefixes fun. Students can race the clock to see how well they have the prefixes memorized.

This site gives a description of regular polygons along with visual representations of several polygons. There are links to related terms, everyday examples, challenging problems, more information, and the interactive check point...

With a brief story and photo of an image, students will do some digging to figure out how old the object pictured is and the history behind it.

Why are airport runways numbered? The math challenge is to figure out the missing runway number.

Does he have a chance? In this math challenge, estimate Helix's chances of winning the bowling tournament.

How far can you fly a paper airplane? Math challenge provides practice in comparing quantities.

How do I cover thee? Let me count the ways. The challenge is to figure out in how many ways can the Tatami mats be arranged to cover the floor.

Is the Statue of Liberty's nose too long? Challenge is to figure out the length of the Statue of Liberty's nose by knowing the length of her arm.

Math activity challenges you to figure out how fast an Arctic tern can fly around the world. How long would it take to fly from the Arctic to the Antarctic and back?

Math activity challenges you to determine how many different ways there are to get to your destination.

How do you print a ribbon on a box? The challenge is to figure out which of the patterns can be folded into a box with an orange ribbon printed all the way around it?

Rome's power is challenged by kingdoms in the East, especially Philip V of Macedonia. After three wars against Macedonia and one against Antiochus of Syria, Rome shows her strength.