**Students take on the role of engineers and generate multiple designs for a physical model based on a set of criteria and constraints for keeping people safe while crossing a crevasse. Students develop empathy around the danger a crevasse poses for those who travel across snowy terrain. They practice brainstorming skills and later apply them in the culminating design challenge at the end of the unit. Students explore the different types of internal forces that act on building materials and investigate ways of increasing the strength of materials to withstand the applied forces. Students learn about variables, failure points, and conducting fair test by building a structure from straws and connectors. These skills are applied in the design challenge where students prototype a crevasse-crossing solution, identify failure points and variables through fair testing, and then refine the design according to a set of criteria and constraints. This design-focused unit was developed in collaboration with The Tech Museum of Innovation in San Jose, California and the San Jose Public Library.**

**Educational outcomes**

- Students will synthesize information from videos and discussions to write an informational text piece
- Students will learn, practice, and apply effective brainstorming skills
- Students will identify and describe the internal forces that affect the strength of materials
- Student teams will build a structure and identify variables and failure points that affect its structural integrity
- Student teams will test and iterate as they build a model of a solution for safely crossing a crevasse that meets defined criteria and constraints

**STEAM INTEGRATION**

Students write informative texts on ways of preventing people from falling into a crevasse based on information learned through multiple sources (W.3.2). Students investigate the internal forces acting on materials to provide evidence of balanced and unbalanced forces and use the information to develop ways to increase the strength of specific building materials (3-PS2-1). Students build a simple structure and consider its failure points and variables to identify aspects that can be improved (3-5-ETS1-3). Students practice generating multiple possible solutions to a problem via brainstorming based on how well each is likely to meet the criteria and constraints of the problem (3-5-ETS1-2). During the design challenge students engage in the steps of the design process to generate, compare, and test a solution against criteria and constraints (3-5-ETS1-2)(3-5-ETS1-3).