Interactive
Other

Calculator.net: Volume Calculator

For Students 6th - 8th Standards
Use these calculator tools to find the volume, in your choice of units, of a sphere, cone, cube, cylinder, rectangular prism, capsule, ball cap, conical frustum, ellipsoid, or square pyramid. Includes a reference section listing formulas...
Lesson Plan
Other

West Contra Costa Usd: Volume: A Foundation in Unit Cubes [Pdf]

For Teachers 4th - 6th Standards
A very detailed instructional activity on determining the volume of rectangular prisms, teaching students how to derive the formula for volume, and to use it successfully. Plenty of examples, student work, and assessment options.
Interactive
Other

Calculator.net: Surface Area Calculator

For Students 6th - 8th Standards
Use these calculator tools to find the surface area, in your choice of units, of a sphere, cone, cube, cylinder, rectangular prism, capsule, ball cap, conical frustum, ellipsoid, or square pyramid. Includes a reference section listing...
Interactive
National Council of Teachers of Mathematics

Nctm: Illuminations: Cubes

For Students 3rd - 5th Standards
Use this applet to determine the volume of a box by filling it with cubes, rows of cubes, or layers of cubes. Determine the surface area as well by using the box's net.
Activity
University of Cambridge

University of Cambridge: Nrich: Making Boxes

For Students 3rd - 8th Standards
Have fun and learn by making a box and then find out its maximum volume as well as other problem-solving activities, including making a table of your results and drawing a graph.