Bobby started today's class with a lesson about tension and compression. After demonstrating the different concepts she split them into groups and gave set them to work on a computer applet. Using the program the students built bridges. As they built Bobby discussed the concept of nodes and other variables required in the applet.
Once they were comfortable with the applet Bobby set up a challenge: whoever could best minimize tension and compression in their bridge would win! After break they continued the contest, with Mauricio emerging as the victor.
The rest of the morning was spent preparing for tomorrow's activity. They will be building structures out of cups and straws to see whose is tallest and can hold the most marbles.