Projections and coordinates are key advancements in the geographic sciences that allow us to better understand the nature of the Earth and how to describe location. These innovations in describing the Earth are the basis for everything that is done in a GIS framework. Shape of the Earth is a critical starting point because in fact the Earth is not round but rather a more complex shape called a geoid. Coordinate systems are often referenced to a particular model shape of the Earth, but many different formats exist because not all coordinates work equally well in all areas. While projections and coordinates are abstract concepts in themselves, students eventually find them interesting because 1) it causes them to challenge their current ideas of the Earth's shape and 2) it is much easier to visualize these ideas for learning through interactive GIS such as Google Earth.

Students experience the steps of the engineering design process as they design solutions for a real-world problem that could affect their health. After a quick review of the treatment processes that municipal water goes through before it comes from the tap, they learn about the still-present measurable contamination of drinking water due to anthropogenic (human-made) chemicals. Substances such as prescription medication, pesticides and hormones are detected in the drinking water supplies of American and European metropolitan cities. Using chlorine as a proxy for estrogen and other drugs found in water, student groups design and test prototype devices that remove the contamination as efficiently and effectively as possible. They use plastic tubing and assorted materials such as activated carbon, cotton balls, felt and cloth to create filters with the capability to regulate water flow to optimize the cleaning effect. They use water quality test strips to assess their success and redesign for improvement. They conclude by writing comprehensive summary design reports.

Students are introduced to the (hypothetical) task of developing an invisible (non-intrusive) security system to protect the school's treasured mummified troll! Solving the challenge depends on an understanding of the properties of light. After being introduced to the challenge question, students generate ideas and consider the knowledge required find solutions. They watch a portion of the "Mythbuster's Crimes and Myth-Demeanors" episode ($20), which helps direct their research and learning toward solving the challenge. They begin to study laser applications in security systems, coming to realize the role of lasers in today's society.

Students learn how simple machines, including wedges, were used in building both ancient pyramids and present-day skyscrapers. In a hands-on activity, students test a variety of wedges on different materials (wax, soap, clay, foam). Students gain an understanding of how simple machines are used in engineering applications to make our lives and work easier.

Students analyze a cartoon of a Rube Goldberg machine and a Python programming language script to practice engineering analysis. In both cases, they study the examples to determine how the different systems operate and the function of each component. This exercise in juxtaposition enables students to see the parallels between a more traditional mechanical engineering design and computer programming. Students also gain practice in analyzing two very different systems to fully understand how they work, similar to how engineers analyze systems and determine how they function and how changes to the system might affect the system.

Working in small groups, students complete and run functioning Python codes. They begin by determining the missing commands in a sample piece of Python code that doubles all the elements of a given input and sums the resulting values. Then students modify more advanced Python code, which numerically computes the slope of a tangent line by finding the slopes of progressively closer secant lines; to this code they add explanatory comments to describe the function of each line of code. This requires students to understand the logic employed in the Python code. Finally, students make modifications to the code in order to find the slopes of tangents to a variety of functions.

Students explore the applications of quantum dots by researching a journal article and answering framing questions used in a classwide discussion. This "Harkness-method" discussion helps students become critical readers of scientific literature.

Students practice converting between RGB and hexadecimal (hex) formats. They learn about mixing primary colors in order to get the full spectrum of colors and how to average pixel values.

Explore forces, energy and work as you push household objects up and down a ramp. Lower and raise the ramp to see how the angle of inclination affects the parallel forces acting on the file cabinet. Graphs show forces, energy and work.

This lesson will start with a brief history of robotics and explain how robots are beneficial to science and society. The lesson then will explore how robots have been used in recent space exploration efforts. The engineering design of the two Mars rovers, Spirit and Opportunity, will be used as prime examples. Finally, the maneuverability of their robotic arms and the functionality of their tools will be discussed.

The discovery of restriction enzymes and their applications in DNA analysis has proven to be essential for biologists and chemists. This lesson focuses on restriction enzymes and their applications to DNA analysis and DNA fingerprinting. Use this lesson and its associated activity in conjunction with biology lessons on DNA analysis and DNA replication.

Watch a reaction proceed over time. How does total energy affect a reaction rate? Vary temperature, barrier height, and potential energies. Record concentrations and time in order to extract rate coefficients. Do temperature dependent studies to extract Arrhenius parameters. This simulation is best used with teacher guidance because it presents an analogy of chemical reactions.

Students build on their understanding and feel for flow rates, as gained from the associated Faucet Flow Rate activity, to estimate the flow rate of a local river. The objective is to be able to relate laboratory experiment results to the environment. They use the U.S. Geological Survey website (http://waterdata.usgs.gov/nwis/rt) to determine the actual flow rate data for their river, and compare their estimates to the actual flow rate. For this activity to be successful, choose a nearby river and take a field trip or show a video so students gain a visual feel for the flow of the nearby river.

Students learn various topics associated with the circle through studying a clock. Topics include reading analog time, understanding the concept of rotation (clockwise vs. counter-clockwise), and identifying right angles and straight angles within circles. Many young students have difficulty telling time in analog format, especially with fewer analog clocks in use (compared to digital clocks). This includes the ability to convert time written in words to a number format, for example, making the connection between "quarter of an hour" to 15 minutes. Students also find it difficult to convert "quarter of an hour" to the number of degrees in a circle. This activity incorporates a LEGO® MINDSTORMS® NXT robot to help students distinguish and visualize the differences in clockwise vs. counter-clockwise rotation and right vs. straight angles, while learning how to tell time on an analog clock. To promote team learning and increase engagement, students work in teams to program and control the robot.

Students learn and practice how to find the perimeter of a polygonal shape. Using a ruler, they measure model rooms made of construction paper walls. They learn about other tools, such as a robot, that can help them take measurements. Using a robot built from a LEGO® MINDSTORMS® NXT kit that has been programmed to move along a wall and output the length of that wall, students record measurements and compare the perimeter value found with the robot to the perimeter found using a ruler. In both cases, students sketch maps to the scale of the model room and label the measured lengths. A concluding discussion explores the ways in which using a robot may be advantageous or disadvantageous, and real-world applications.

Students learn about probability through a LEGO® MINDSTORMS® NTX-based activity that simulates a game of "rock-paper-scissors." The LEGO robot mimics the outcome of random game scenarios in order to help students gain a better understanding of events that follow real-life random phenomenon, such as bridge failures, weather forecasts and automobile accidents. Students learn to connect keywords such as certainty, probable, unlikely and impossibility to real-world engineering applications.

Students are presented with a challenge question that they must answer with scientific and mathematical reasoning. The challenge question is: "You have a large rock on a boat that is floating in a pond. You throw the rock overboard and it sinks to the bottom of the pond. Does the water level in the pond rise, drop or remain the same?" Students observe Archimedes' principle in action in this model recreation of the challenge question when a toy boat is placed in a container of water and a rock is placed on the floating boat. Students use terminology learned in the classroom as well as critical thinking skills to derive equations needed to answer this question.

In this activity, students revisit the Pop Rockets activity from Lesson 3. This time, however, the design of their pop-rockets will be limited by budgets and supplies. They will get a feel for the limitations of a real engineering project as well as an opportunity to redesign and retest their rockets.

Students learn about rotary encoders and discover how they operate through hands-on experimentation. Rotary encoders are applied in tools to determine angle measurements and for translations of angular motion. One common rotary encoder application is in a computer's ball-type mouse—the ball itself is a type of rotary encoder. In this activity, students experiment with two rotary encoders, including one from a computer mouse and one created using a LEGO® MINDSTORMS® NXT kit. They collect data to define and graph the relationship between the motion of the rotary encoder and its output.

Add different salts to water, then watch them dissolve and achieve a dynamic equilibrium with solid precipitate. Compare the number of ions in solution for highly soluble NaCl to other slightly soluble salts. Relate the charges on ions to the number of ions in the formula of a salt. Calculate Ksp values.