Today's task was to design a bridge that held the most pennies. The challenge? Each bridge could only use one index card, no glue or tape, no weighted down sides, and the two bases had to be a distance of 10 cm apart. The first attempts were different versions of index cards laid flat across the bases. These yielded results of around 30 pennies. As the students heard teams shout out their penny amounts, the competition grew more fierce. Suddenly, kids were scrambling to build stronger, more complex bridges. After many trials, we found that the bridge design that held the most pennies was an index card folded about a half centimeter up on both long sides, like a railing. The most pennies any one bridge held was 210. That's a lot of pennies!