Asking questions and defining problems to formulate, refine, and evaluating testable questions and design problems using models and simulations.
Using Mathematics and Computational Thinking
 Mathematical and computational thinking uses algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials, and logarithms, and computational tools for statistical analysis to analyze, represent, and model data.
 Simple computational simulations are created and used based on mathematical models of basic assumptions.
 Use mathematical models and/or computer simulations to predict the effects of a design solution on systems and/or the interactions between systems.
 Use mathematical models and/or computer simulations to predict the effects of a design solution on systems and/or the interactions between systems.
 Constructing explanations and designing solution progresses to explanation and designs that are supported by multiple and independent studentgenerated sources of evidence consistent with scientific ideas, principles, and theories.
 Evaluate a solution to a complex, realworld problem, based on scientific knowledge, studentgenerated sources of evidence, prioritized criteria, and tradeoff considerations. (HSETS13)

Defining and Delimiting Engineering Problems
 Criteria and constraints also include satisfying requirements set by society, such as taking issues of risk mitigation into account, and they should be quantified to the extent possible and state in such a way that one can tell if a given design meets them.
Developing Possible Solutions
 When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics and to consider social, cultural, and environmental impacts.
 Both physical models and computers can be used in various ways to aid in the engineering design process. Computers are useful for a variety of purposes, such as running simulations to test different ways of solving a problem or to see which one is most efficient or economical; and in making a persuasive presentation to a client about how a given design will meet needs.
Optimizing the Design Solution
 Criteria may need to be broken down into simpler ones that can be approached systematically, and decision about the priority of certain criteria over others (tradeoffs) may be needed. (HSETS12)

Systems and Systems Models
 Models (physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales. (HsETS14)
Influence of Science, Engineering, and Technology on Society and the Natural World
 New technologies can have deep impacts on society and the environment, including some that were not anticipated. Analysis of costs and benefits is a critical aspect of decision about technology. (HSETS11) HSETS13)
