What causes an area to have poor air quality? Use this model to explore the connections between pollution sources, weather, geography, and air quality. Discover which weather condition causes the development of additional air pollutants. Compare the effects of two different pollution sources, pollution-control devices, and changing weather conditions on the air quality over a city.

Use tiles to represent variables and constants, learn how to represent and solve algebra problems. Solve equations, substitute in variable expressions, and expand and factor. Flip tiles, remove zero pairs, copy and arrange, and make your way toward a better understanding of algebra.

Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.

Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.

An interactive applet and associated web page that demonstrate the alternate exterior angles that are formed where a transversal crosses two lines. The applets shows the two possible pairs of angles alternating when in animation mode. By dragging the three lines, it can be seen that the angles are congruent only when the lines are parallel. When not in animated mode, there is a button that alternates the two pairs of angles. The text on the page discusses the properties of the angle pairs both in the parallel and non-parallel cases. 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 demonstrate the alternate interior angles that are formed where a transversal crosses two lines. The applets shows the two possible pairs of angles alternating when in animation mode. By dragging the three lines, it can be seen that the angles are congruent only when the lines are parallel. When not in animated mode, there is a button that alternates the two pairs of angles. The text on the page discusses the properties of the angle pairs both in the parallel and non-parallel cases. 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.

American Red Cross First Aid-CPR-AED Resources:Responding to Emergencies: Comprehensive First Aid, CPR, and AED. American Red Cross is the Author and publisher of these resource materials.

An interactive applet and associated web page that introduce the concept of an angle. An angle made from two line segments is shown that the user can adjust by dragging the end points of the segments. In real time, as the angles is changed by the user, the angle measure in degrees is shown and a message telling what type of angle it currently is: acute, right, obtuse, reflex or straight. 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 demonstrate the bisector of an angle. An angle is shown using two line segments that can be dragged to change the angle measure. The angle is bisected by a line which moves while dragging to always divide the angle into two equal angles. The angle measures can be turned off for class discussions. 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 that acts as a 'digital manipulative' for explaining angles measured in degrees. The applet has an angle formed from two segment that can be dragged around in a circle. The angle measure is shown against a 'clock face' calibrated in degrees. The measures can be turned off for class angle estimation discussions. 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.

This is a project based lesson focused on behavioral and physical adaptations of animals.

In the explorable explanation players can learn how antibiotic resistance happens. They can interact with bacteria in this simulation to learn how when living things reproduce, there is a small amount of variance in their offspring. This allows organisms to respond to changes in their environment over several generations. Applied to bacteria, when they treated with antibiotics, only the strongest survive and multiply, creating an increasing resilient population.

We use the derivative to determine the maximum and minimum values of particular functions (e.g. cost, strength, amount of material used in a building, profit, loss, etc.).Differentiation is also used in analysis of finance and economics.

An interactive applet and associated web page that demonstrate the concept of an arc. The applet shows a circle with part of it highlighted to identify the arc. Each endpoint of the arc can be dragged to resize it. The web page has definitions and links to the properties of an arc. 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 demonstrate the concept of arc length. The applet shows a circle with part of its circumference highlighted and the central angle shown. As the user drags either end of the arc it is redrawn and the calculation for arc length changes as you drag. The text on the web page gives the formula for calculating the arc length. 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.

This activity is best placed as a follow-up activity to the study of minerals and the three major rock types in an introductory physical geology course. Students are required to work in small cooperative groups. Each group chooses a major building to research. The group divides the tasks associated with the research and presentation of information. The overall goal of the project is for students to gain an understanding of the importance and uses of earth materials in building and planning major buildings in an urban setting.

The general format of the project is:
1. Students research building design, placement and use of earth materials in a major building.
2. Students research the earth materials used in their building.
3. Students create and show their PowerPoint presentation in class.
4. Students prepare and deliver an on-site oral presentation about their building.

The activity helps students connect a basic study of earth materials to urban planning and living.

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Create your own shapes using colorful blocks and explore the relationship between perimeter and area. Compare the area and perimeter of two shapes side-by-side. Challenge yourself in the game screen to build shapes or find the area of funky figures. Try to collect lots of stars!

Build rectangles of various sizes and relate multiplication to area. Discover new strategies for multiplying algebraic expressions. Use the game screen to test your multiplication and factoring skills!

Build rectangles of various sizes and relate multiplication to area. Partition a rectangle into two areas to discover the distributive property.

Build rectangles of various sizes and relate multiplication to area. Discover new strategies for multiplying large numbers. Use the game screen to test your problem solving strategies!