PROMOTING THE TWENTYFIRSTCENTURY SKILLS
The trafficjam problem clearly gives the students an opportunity to engage in communication, collaboration, critical thinking, and creative problem solving, the four pillars of twentyfirstcentury skills. The problem allowed the students to begin the work they were assigned without any bias or opinions about what is or is not expected from the task. The misconceptions and misrepresentation that arose in the process helped them to get a better insight. Such student insights often open up new problemsolving strategies or even questions overlooked by the teacher.
The process of mathematical modeling provided students with opportunities to develop their twentyfirstcentury skills (P21) Learning and Innovation Skills which emphasize the 4 Cs: communication, collaboration, creativity, and critical thinking (see Table 3.1).
Mathematical modeling challenges students to use their mathematics communication as they collaborate on a problem. Students also use creative problem solving and critical thinking as they work to identify variables and make assumptions to build a mathematical model. In one of our STEM lesson studies, we had students designing a package that was environmentally friendly (Suh, Seshaiyer, Moore, Green, Jewell, & Rice, 2013).
In the project, Being an Environmentally Friendly Package Engineer, students were given objects for which they needed to design a package. They were given a large
Table 3.1 Twentyfirstcentury skills (Partnership for 21st Century Skills, 2011)
Critical Thinking and Creativity Reason Effectively/Use Systems Thinking 1. Use various types of reasoning (inductive, deductive, etc.) as appropriate to the situation 
Make Judgments and Decisions

Solve Problems

Work Creatively with Others 1. Demonstrate originality and inventiveness in work and understand the realworld limits to adopting new ideas 
Collaborate with Others 1. Demonstrate ability to work effectively and respectfully with diverse teams. Assume shared responsibility for collaborative work, and value the individual contributions made by each team member 
Communication

graph paper to create a prototype. One group created a “4 x 4 x 4” cube and then realized that they had a lot of wasted space. The student decided to redesign the package into a “4 x 4 x 2” rectangular prism in order to use more space, to be costefficient, and more ecofriendly (see Figure 3.8). To evaluate their design, students were asked to calculate the volume for their packages and the surface area.
The design phase involved an iterative cycle. Students created their prototype after discussion and then altered and modified the design based on the following factors: efficiency of space, economical, ecofriendly, or appealing design. An evaluation criterion was to decide which packaging design was most efficient. Students had to negotiate as they collaborated on their design. In the 5/6 uppergrade classrooms, we were able to provide the same scenario to explore packages but added more creative designs including cylinders and triangular prisms.
An interesting discussion that the class had was to think about what determines the best packaging container. If you want a package for something without a particular shape of its own, and minimize the amount of packaging material used, a sphere is the most efficient because it has the lowest surfacetovolume ratio of any geometric solid. In addition, round containers are generally used for any application requiring great strength. However, if all the packages were spheres like a soccer ball, packing multiple sphere packages would create empty space between containers. So if you are trying to pack something into multiple containers, the sphere is not the most efficient shape. Instead, a rectangular prism or cube might be the most efficient. This was a
Table 3.2 Prompts for students to selfassess and peerassess after a problemsolving task
Assessing your Twentyfirstcentury Learning Skills in Mathematics 

Prompts to assess your 4 Cs contribution 
Critical Thinking: How did you solve this problem in new ways linking what you know? 
Creativity: What new approaches did you consider to solve this problem or did you invent a strategy that was efficient? 
Communication: Did you share thoughts, questions, and solutions? 
Collaboration: How did you work together to each a goal, using your knowledge, talents, and skills? 
Selfassessment 

Peer group 
great discussion to have about why most realworld packaging is boxshaped rather than spherical.
Assessing student skills and knowledge is essential to guide learning and provide feedback to both students and teachers on how well they are doing in reaching desired twentyfirstcentury learning goals (Trilling & Fadel, 2009). Some of the ways to assess students’ twentyfirstcentury skills are to use a simple assessment rubric (see Table 3.2). Selfassessing one’s own contribution to group projects can help develop students’ selfmonitoring skills and accountability in group collaboration.
Figure 3.8 The packaging iterative design phases.
Think about it!
How does the mathematical modeling process prepare our students to be creative problem solvers for the 21st century?