The final activity of this unit, which integrates the Keepers of the Gate unit through the Go Public challenge, involves students taking part in experimental design. They design a lab that answers the challenge question: "You are spending the night with your grandmother when your throat starts to feel sore. Your grandma tells you to gargle with salt water and it will feel much better. Thinking this is an old wive's tale, you scoff, but when you try it later that night it works! Why?" Students must have their plan approved by the instructor before they begin. A formal lab write-up is due as part of the laboratory investigation.

This task presents a real-world problem requiring the students to write linear equations to model different cell phone plans. Looking at the graphs of the lines in the context of the cell phone plans allows the students to connect the meaning of the intersection points of two lines with the simultaneous solution of two linear equations.

This simple task assesses whether students can interpret function notation. The four parts of the task provide a logical progression of exercises for advancing understanding of function notation and how to interpret it in terms of a given context.

In this lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. And, students are introduced to the process of bioremediation and several examples of how bioremediation is used during the cleanup of environmental contaminants.

Two lessons and their associated activities explore cellular respiration and population growth in yeasts. Yeast cells are readily obtained and behave predictably, so they are very appropriate to use in middle school classrooms. In the first lesson, students are introduced to yeast respiration through its role in the production of bread and alcoholic beverages. A discussion of the effects of alcohol on the human body is used both as an attention-getting device, and as a means to convey important information at an impressionable age. In the associated activity, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arise from this activity, in the second lesson students work in small groups as they design and execute their own experiments to determine how environmental factors affect yeast population growth.

The purpose of this task is to use geometric and algebraic reasoning to model a real-life scenario. In particular, students are in several places (implicitly or explicitly) to reason as to when making approximations is reasonable and when to round, when to use equalities vs. inequalities, and the choice of units to work with (e.g., mm vs. cm).

Student groups compete to design a process that removes the most iron from fortified cereal. Students experiment with different materials using what they know about iron, magnets and forces to design the best process for removing iron from the cereal samples.

Students become familiar with the engineering design process as they design, build and test chair prototypes. The miniature chairs must be sturdy and functional enough to hold a wooden, hinged artist model or a floppy stuffed animal. They use their prototypes to assess design strengths and weaknesses.

Students teams use a laparoscopic surgical trainer to perform simple laparoscopic surgery tasks (dissections, sutures) using laparoscopic tools. Just like in the operating room, where the purpose is to perform surgery carefully and quickly to minimize patient trauma, students' surgery time and mistakes are observed and recorded to quantify their performances. They learn about the engineering component of surgery.

At its core, the LEGO MINDSTORMS(TM) NXT product provides a programmable microprocessor. Students use the NXT processor to simulate an experiment involving thousands of uniformly random points placed within a unit square. Using the underlying geometry of the experimental model, as well as the geometric definition of the constant π (pi), students form an empirical ratio of areas to estimate a numerical value of π. Although typically used for numerical integration of irregular shapes, in this activity, students use a Monte Carlo simulation to estimate a common but rather complex analytical form the numerical value of the most famous irrational number, π.

This lesson begins with an activity in which students induce EMF in a coil of wire using magnetic fields. Then, demonstrations on Eddy currents show how a magnetic field can slow magnets just as Eddy currents are used to slow large trains. There is then a demonstration in which a loop "jumps" because of a changing magnetic field. Finally, formal lecture reviews the cross product with respect to magnetic force and introduces magnetic flux, Faraday's law of Induction, Lenz's Law, Eddy currents, motional EMF and Induced EMF.

Students use balloons to perform several simple experiments to explore static electricity and charge polarization.

Similar to how Charlotte uses her web to communicate, students create webs for short messages. They learn how spiders create their webs, and about the different types of webs they make. With this knowledge, students design and create their own webs and incorporate messages.

The purpose of the task is to connect properties of fractional exponents with ordering of real numbers. One can place the numbers on the number line to emphasize this.

This lesson introduces the concepts of wavelength and amplitude in transverse waves. In the associated activity, students will use ropes and their bodies to investigate different wavelengths and amplitudes.

Students are introduced to chemical engineering and learn about its many different applications. They are provided with a basic introduction to matter and its different properties and states. An associated hands-on activity gives students a chance to test their knowledge of the states of matter and how to make observations using their five senses: touch, smell, sound, sight and taste.

Student groups are given captioned photographs of the Chernobyl Nuclear Power Plant facility and surrounding towns taken before and 28 years after the 1986 disaster. Based on the captions and clues in the images, they arrange them in sequential order. While viewing the completed sequence of images, students reflect on what it might have been like to be there, and ask themselves: what were people thinking, doing and saying at each point? This activity assists students in gaining an understanding of how devastating nuclear meltdowns can be, which underscores the importance of responsible engineering. It is recommended that this activity be conducted before the associated lesson, Nuclear Energy through a Virtual Field Trip.

This problem includes a percent increase in one part with a percent decrease in the remaining and asks students to find the overall percent change. The problem may be solved using proportions or by reasoning through the computations or writing a set of equations.

This task presents a real world situation that can be modeled with a linear function best suited for an instructional context.

This task is intended strictly for instructional purposes with the goal of building understandings of linear relationships within a meaningful and, hopefully, somewhat familiar context.