Pennies have a monetary face value of one cent, but they are made of material that has a market value that is usually different. It is the value of the materials that requires attention in this problem. While it is interesting to compare the face value with the value of the materials, this does not have any bearing on the calculations. Interference between these two notions of value is a possible area of difficulty for some students.

As written, this problem gives students all of the information they need to estimate the thickness of a soda can.

his is a version of ''How thick is a soda can I'' which allows students to work independently and think about how they can determine how thick a soda can is. The teacher should explain clearly that the goal of this task is to come up with an ''indirect'' means of assessing how thick the can is, that is directly measuring its thickness is not allowed.

In this problem-based learning (PBL) activity, students take on the role of a student research scientist and explore the role of solar energy in determining climate. Students conduct experiments to observe how a change in water phase affects surface temperatures. Materials required for the investigation include 2 aquariums, dry sand or soil, two heat lamps, and two thermometers.The lesson is supported by teacher notes, answer key, glossary and an appendix with information about using PBL in the classroom. This is the second of three activities in Investigating the Climate System: Energy, a Balancing Act.

The purpose of this task is to continue a crucial strand of algebraic reasoning begun at the middle school level (e.g, 6.EE.5). By asking students to reason about solutions without explicily solving them, we get at the heart of understanding what an equation is and what it means for a number to be a solution to an equation. The equations are intentionally very simple; the point of the task is not to test technique in solving equations, but to encourage students to reason about them.

This task can be used as a quick assessment to see if students can make sense of a graph in the context of a real world situation. Students also have to pay attention to the scale on the vertical axis to find the correct match.

These problems are meant to be a progression which require more sophisticated understandings of the meaning of fractions as students progress through them.

This task provides a context for performing division of a whole number by a unit fraction. This problem is a "How many groups?'' example of division.

Students measure and analyze forces that act on vehicles pulling heavy objects while moving at a constant speed on a frictional surface. They study how the cars interact with their environments through forces, and discover which parameters in the design of the cars and environments could be altered to improve vehicles' pulling power. This LEGO® MINDSTORMS® based activity is geared towards, but not limited to, physics students.

In this lesson, students will learn how great navigators of the past stayed on course that is, the historical methods of navigation. The concepts of dead reckoning and celestial navigation are discussed.

An interactive applet and associated web page that provide step-by-step animated instructions on how to measure angles using a protractor. Specifically, it uses a protractor to measure two angles that form a vertical pair, verifying they have the same measure. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that provide step-by-step animated instructions on how to use a protractor to draw an angle. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Students learn the patterns in the hundred board by assembling puzzles. Teachers are able to assess student use of patterns in rows and columns by observing the student at work. This task is easily differentiated to accommodate the varied levels in a first grade class by changing the number of pieces and the shape of the pieces. Puzzle bags should be sequentially lettered so that students progress through harder versions of the task. Finally, students are asked to create their own puzzles for classmates to solve.

Students use "magic" to navigate around the hundred board. This activity introduces horizontal arrows which mean move one square in the direction the arrow points and vertical arrows which mean move up or down one row in the direction the arrow points. These activities support students as they develop understanding of powerful number patterns in the hundred board: (1) moving across or back one space means adding or subtracting one from the starting number; (2) moving up or down one row means adding or subtracting ten from the starting number; (3) combining a series of arrows is the same as adding or subtracting a two-digit number. These activities build upon the understanding of counting on and counting back by one. The arrow magic routines challenge students to develop strategies for counting on and back by ten.

Students play a game in pairs to read and recognize numbers using a 100 chart.

In this activity, learners will use a hurricane tracking map, satellite images and weather maps to track a hurricane and predict its path. They will consider the meaning and appropriate use of a hurricane watch and a hurricane warning and how these impact public action. They will discuss the hurricane's path and their predictions in a simulated debriefing session and television appearance. Links to maps, data and images are provided. This activity is part of the Event-Based Science (EBS): Remote Sensing Activities.

This is an animation of a square rotating in hyperbolic geometry as represented by the Poincaré Disk Model.

This image is a hyperbolic tiling made from alternating two shapes: heptagons and triangles. This image is a hyperbolic tiling made from alternating two shapes: heptagons and triangles. This image is a hyperbolic tiling made from alternating two shapes: heptagons and triangles. This image is a hyperbolic tiling made from alternating two shapes: heptagons and triangles. This image is a hyperbolic tiling made from alternating two shapes: heptagons and triangles.