Learning goals
- Surface area measures the outside wrapper of a solid.
- A rectangular prism has three pairs of congruent faces.
- Surface area and volume answer different questions even for the same box.
Surface area as a wrapper
Unfold a rectangular prism into six faces and add the visible rectangles.
A net is a 3-D solid unfolded flat. Unfolding a rectangular prism gives six rectangles you can measure separately — and surface area becomes the sum of those six visible areas, not a memorized formula.
Aligned with CCSS 6.G.A.4 (represent three-dimensional figures using nets and use nets to find surface area).
Unfold a box into its flat net to see surface area = sum of the 6 faces = 2(LW + LH + WH).
S = 2(3×2 + 3×2 + 2×2) = 32
Geometry and measurement model
Surface Net Unfolder is built for students who memorize formulas before seeing the shape decomposition. It gives the page a clear search purpose: learn the model, manipulate it, then continue into the matching grade-level practice.
Surface Net Unfolder helps when a student can copy a procedure but cannot explain why it works. The demo slows the idea down into a visible model before sending the learner to guided missions.
Learning goals
How to play
Continue with guided practice
Surface area measures the outside wrapper (cm²). Volume measures the inside fill (cm³). Doubling a side affects them at different rates — 4× and 8× respectively.
The top equals the bottom, front equals back, left equals right — same length × width pairs in each case. So SA = 2(LW + LH + WH).
Because it makes every face measurable on flat paper. Hard-to-see hidden faces become visible side-by-side.
Grade 6, aligned with CCSS 6.G.A.4. Foundation for surface area of cylinders and pyramids in Grades 7–8.