Science Background

Throughout the grade 3 curriculum, students will work with a set of materials cubes. These are 8 cubes that are of equal shape and size, but made of different materials. By comparing these cubes to each other in a variety of ways, learners will discover that objects with equal volume may have very different weights, depending on the material they are made of. Each cube is approximately 1 inch or 2.5 cm on each side. The volume is 1 cubic inch or 15.6 cubic cm. If cubes are not marked, label each cube as shown below.

The Material Cubes

Pine (Pi):

The lightest cube is made of wood from a pine tree. The mass of this cube is approximately 7 gm. The mass may vary slightly. Pine is a soft wood that is used for furniture and timber. Pine is a low density wood, because it comes from fast growing trees.

Oak (Oa):

The second wooden cube is made from an oak tree. Oak is a much stronger and harder wood than pine. Oak has a greater density than the pine cube, so this cube is heavier. It’s mass is approximately 13 gm. It is also typically darker in color than pine.

Nylon (Ny):

The nylon cube is white and plastic. Nylon is made from petroleum products. Nylon is often used to make fabric (an inexpensive alternative to silk), but can also be made into a hard plastic, as is this cube. The mass of the nylon cube is approximately 18 gm.

Acrylic (Ac):

The acrylic cube appears as a clear plastic. Because acrylic is clear, as well as stronger and less dense than glass, it is often used for outdoor windows and skylights. Acrylic is a term referring to man–made materials containing some form of acrylic acid. The mass of the acrylic cube is approximately 19 gm.

PVC (PV):

The PVC cube is grey and plastic. PVC stands for Polyvinyl Chloride which is an inexpensive and very durable material, often used in vinyl siding, magnetic stripe cards, and pipes for plumbing. Although the production of PVC is dangerous to health and the environment, it is one of the largest revenue generators of the chemical industry. The mass of the PVC cube is approximately 22 gm.

Aluminum (Al):

The aluminum cube is shiny and silver-colored. Its low density and strength makes it ideal for the construction of airplanes and other vehicles. Aluminum is the most abundant element in Earth’s crust. The mass of the aluminum cube is approximately 44 gm.

Steel (St):

The steel cube is black and metal. Steel is an alloy of mostly iron and a bit of carbon. The symbol for iron in the periodic table is Fe, which is the stamp on the cube. The addition of carbon makes it stronger than Iron, but also more brittle. Steel is often used in the construction of buildings and vehicles. The mass of the steel cube is approximately 128 gm.

Copper (Co):

The copper cube is reddish-brown and metal. Copper is a natural element with the symbol Cu in the periodic table. Because of its high ability to conduct electricity, copper is often used for electrical wires and computer circuit boards. It is also used to make pennies, but since the rise in price of copper in the 1980’s it is now only used as a coating over other metals. The mass of the copper cube is approximately 147 gm.