Grade 3 & 4
Strength and Stability

Strength and Stability

The early part of the engineering unit focused on what makes structures strong and stable. Our first lesson was learning about the force that is always acting on the world – gravity. The students were given a similar number of marshmallows and toothpicks and their challenge, within the time limit, was to build the tallest structure that can hold a tennis ball for a period of time. Some groups focused on strengthening a single level, while other groups stretched their resources and attempted a second layer. What the groups found was that the students that went higher had more difficulty holding up the tennis ball due to gravity.

The next topic was figuring out what the strongest beam and post shape was. Using paper in different configurations, students placed beans and novels on top of beams and columns to investigate which shape can hold the most weight, while staying upright. Students found that the more folds in a paper (beams) and the circular column were the strongest shapes.

 

Next, students are looking at different materials that structures can be made of and what materials would be strongest and most stable. The winners were wood, metal, plastic, and rock. As we extend this learning, we are going to look at what material works best and for what structure.