A cost-benefit analysis is a good way to weigh the costs and the benefits and compare them to see if the decisions being made are sound and worthwhile. For a hypothetical solar farm design problem, students are given a solar cost-benefit analysis sheet to complete within groups. They weigh the expense and benefits of two types of solar panels (with different costs, wattage outputs and land impacts), consider the cost of using the acreage for solar (which removes it from ranching use), and explain why they consider the panel combination they propose to be best. If the costs outweigh the benefits, then a project is not worth doing. On the other hand, if the benefits outweigh the costs, then it is worth implementing the plan.

Working as if they are engineers aiming to analyze and then improve data collection devices for precision agriculture, students determine how accurate temperature sensors are by comparing them to each other. Teams record soil temperature data during a class period while making changes to the samples to mimic real-world crop conditions—such as the addition of water and heat and the removal of the heat. Groups analyze their collected data by finding the mean, median, mode, and standard deviation. Then, the class combines all the team data points in order to compare data collected from numerous devices and analyze the accuracy of their recording devices by finding the standard deviation of temperature readings at each minute. By averaging the standard deviations of each minute’s temperature reading, students determine the accuracy of their temperature sensors. Students present their findings and conclusions, including making recommendations for temperature sensor improvements.

Playing the role of engineers in collaborations with the marketing and production teams in a chocolate factory, students design a container for a jumbo chocolate bar. The projects constraints mean the container has to be a regular trapezoidal prism. The design has to optimize the material used to construct the container; that is, students have to find the dimensions of the container with the maximum volume possible. After students come up with their design, teams present a final version of the product that includes creative branding and presentation. The problem-solving portion of this project requires students to find a mathematical process to express the multiple variables in the prism’s volume formula as a single variable cubic polynomial function. Students then use technology to determine the value for which this function has a maximum and, with this value, find the prism’s optimal dimensions.

Student teams investigate the migration of small-particle plastic pollution by exposing invertebrates found in water samples from a local lake or river to fluorescent bead fragments in a controlled environment of their own designs. Students begin by reviewing the composition of food webs and considering the ethics of studies on live organisms. In their model microcosms, they set up a food web so as to trace the microbead migration from one invertebrate species to another. Students use blacklights and microscopes to observe and quantify their experimental results. They develop diagrams that explain their investigations—modeling the ecological impacts of microplastics.

Students collect a large set of data (approximately 60 sets) of individual student’s water use and learn how to use spreadsheets to graph the data and find mean, median, mode, and range. They compared their findings to the national average of water use per person per day and use it to evaluate how much water a municipality would need in the event of a recovery from a water shutdown. This analysis activity introduces students to the concept of central tendencies and how to use spreadsheets to find them.

Global wind patterns are dictated by the movement of the Earth on its axis and are significant factors in determining the climate for regions of the planet. Students learn how the Coriolis effect and Hadley convection cells determine the location of deserts on Earth. They manipulate inflated plastic globes to discover how the Coriolis effect drives wind clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. Then they incorporate latitudinal differences onto this modeling exercise to understand why deserts form at 30 degrees north and south of the equator. Once students understand the importance of global winds, they discuss hydropower in the desert. They compare and contrast two case studies: China’s Three Gorges Dam, and Chile’s proposed plant in the Atacama Desert that would creatively use solar power to move seawater up to the top of a mountain so that it can flow back down and generate power. Students note the economic, environmental, cultural and social impacts, issues and benefits of both power plants. Then they reflect, write, debate and discuss their ideas and opinions using evidence from the case studies and their own research.