Today we had our fifth day of the Parker Hill Library afterschool program, which teaches students to think like engineers. We improved our previous bridge designs using better materials; straws (20 per group) and large marshmallows (20 per group). The bridges needed to be at least 1 foot long, span a gap of 9 inches, and hold as much weight as possible: pennies suspended from a beam within the bridge [see bottom right picture]. Of all the bridges tested, five were able to withstand at least 20 pennies. The top three bridges held 57 pennies (but was only 10 inches long!), 51 pennies, and 51 pennies.