Explicit teaching — I Do (~15 min)
1. Visualising & constructing 3D objects WA6MMGTH1
Show real prisms and pyramids; name them by their cross-section or base (triangular prism, square pyramid). Demonstrate sketching a rectangular prism using oblique projection, then fold a net to construct one.
2. Volume of rectangular prisms WA6MMGTH2
Record the sequence of steps explicitly so students can apply it to any prism.
Guided practice — We Do (~20 min)
- Sort & name. Sort a set of 3D models into prisms versus pyramids; name each by its base.
- Build & count. The class builds several rectangular prisms from cubes and counts volume by layers.
- Derive the steps. Co-construct the step sequence "area of base × height" and test it against the cube counts.
- Apply. Find the volume of three prisms from given dimensions, without building.
Independent practice — You Do (~15 min)
Worksheet/task:
- name given prisms and pyramids by their base;
- sketch a rectangular prism on oblique grid paper;
- determine the volume of rectangular prisms from given dimensions, showing the step sequence;
- one "missing dimension" challenge (given volume and two dimensions, find the third).