We started class with a discussion about buoyancy, mass, volume and surface area. These are the factors that influence density of an object. To show the importance of density, we used an interactive applet that allows users to find the mass, volume, and density of various objects. If you know the density of an object you can compare it to other objects to see if they are made of similar materials. This was portrayed by the story of Archimedes in which he found out how a crown was not pure gold by comparing the density of gold and the density of the crown. The students then observed this themselves by placing various materials in a cup of water to see how much water was displaced. The amount of water displaced tells you the volume of the object, which can help you calculate the mass and density. These three aspects allow the students to identify what the object is made of. The experiment also showed that all materials with a density more than one would sink in the water because water has a density of one. This showed how density and buoyancy are important in the construction of boats. The second half of the workshop was dedicated to building boats that can hold a maximum amount of marbles while also keeping a low manufacturing cost. Each material the students used to build their boat had a price and the team's score depended on the total price of the boat and the efficiency of the boat (the ability to hold marbles). Each team also had to predict how many marbles their boat could hold by using the density formula. The boats were put to the test in a bin full of water and a winner was declared.