Remove all radioactive atoms that have decayed. These are represented by pennies that show heads, sugar cubes with the marked side face up, or dice showing a 1 or 2. Record number on chart.

Surface area is measured in square units including cm² and m². A cube has six congruent square faces. The total area of the faces is the surface area of the cube. To work out the surface area of ...

Faces - A face is a flat surface on a 3D shape. For example a cube has 6 faces. Edges - An edge is where two faces meet. For example a cube has 12 edges. Vertices - A vertex is a corner where ...