How can we make sand stand tall?
What are the positive and negative aspects of using plastic sticks as reinforcement materials?
Learners will test how to best use plastic sticks in reinforcing soil.
Document different amounts, positions, and layers of plastic sticks as reinforcement; calculate the cost of all materials
Summarize what worked and what did not
Test & redesign different amounts, positions, and layers of plastic stick as reinforcement
Competition Announcement (10-15 minutes)
The facilitator will introduce the competition to the students. Students will use the box shown in Figure 1 below. Facilitator will pass around a box for students to review. The goal of the competition is to be able to open the front face of this box and have the soil stand without any support while carrying load. Students can use any or all of the four different reinforcing materials provided to them.
The students will not only consider materials, but should also consider costs. The facilitator will explain that students can mix and match reinforcements provided every group will be given the same sand. After the wall is complete the students will remove the front face of the box and see if there is any deflection. After that a load if 5-kg will be placed on the soil surface and again observed for deflection (such as bulging in the sand or sand falling off). If there is no deflection on the open face the wall passes the test. The wall that satisfies these requirements and costs the lowest wins!
The facilitator will ask students to carefully pass around a 5-kg weight so that students can get a sense of how much weight this is.
The facilitator will ask the students if they have any questions and address them as needed.
Figure 1. Schematic of the box to be used to prepare the soil
Student Group Research
Students should be broken into groups of three. This will be the team they work in and compete with for the remainder of the project. Once split into groups, students should review the design challenge details and the rules of the competition. Each group should make sure that all members of their team understand the rules of the competition and what needs to be accomplished to get to that point.
Note: Students will have the opportunity to mix-and-match materials in a future session, but today’s session will focus exclusively on the plastic stick.
During this phase, it is up to each team to look at the resources available – in this session, plastic sticks – and to plan how best they can be used to complete tasks within the time available. Good planning is the key to any successful project. Every person on the team has a valid contribution to make and every idea should be evaluated on its merits. Students should occasionally check with the job specifications to make sure their ideas are aligned with the learning targets.
Students may use the worksheet above, large butcher paper, or their own journals to take notes, sketch ideas, write down observations, etc.
10 minute break
Students will take their initial plans and experiment with the plastic sticks as a reinforcement for the soil. Each group will work together to test different amounts, positions, and layers of plastic sticks. While constructing, students should not forget to compact the soil. If you do not compact, the reinforcement effects are minimal. Students should be encouraged to continue testing different methods. Students will want to take good notes on what worked during their experimentation - and what didn’t. Students should also take notes on the costs associated with their build for future comparison. Students should be sure to make note of what worked best and how much it cost for future comparisons/considerations.
End of Session Reflection and Debriefing
Teacher briefly explains the computational thinking (CT) skill embedded in the Problem Solving Process Diagram. Using the problem solving process diagram, the teacher will ask students to identify what kind of problem solving skills/process/computational thinking they used in this session and explain how they used it. The following are some sample questions that can guide the debrief.
What did I learn today?
What problem solving skills/processes or CT components in this diagram did I use today?
How did I use the problem solving skills/processes/CT components?