A box of plastic shapes can be an excellent resource to teach three-dimensional shapes for the 11-plus.
Preparation for 11-plus maths can often reveal difficulties with the names of shapes in both two and three dimensions.
While Bond and other text books show the dimensions, representing shapes in 3D using a 2D diagram isn’t always easy.
Lacking a 3D printer, help was needed for one 11-plus candidate – it arrived in the form of a box of plastic shapes – cubes, spheres, cones, cuboids and a pentagonal prism in different sizes and pleasing colours.
Geometric Solids from Learning Resources was bought from Amazon for £14.99 but there are many other versions available.
This is a brilliant resource, firstly, for naming shapes. Hold one hidden in your hand, give the child a quick look, and then ask its name.
Put all the cuboids on the table and ask which one is the cube. That is just for starters.
If a child is able to see and hold the shapes, it is much easier to talk about how the edges measure up on different shapes and how the areas of different faces can be calculated. This is, after all, how volumes can be calculated.
Very cleverly, all the shapes in this particular set have a small removable stopper in them to allow for volumes to be calculated and compared.
They can all be filled with water or flour to help demonstrate how the volume of a cone with a 6cm diameter and 6cm height compares to the volume of a cylinder with the same height but a 3cm diameter.
The answers might be intuitive but showing how the quantity of flour or water measures up to what you expect is a decent way to spend an hour.
And there’s another thing – the shapes proved to be a pretty good toy. The spheres can be rolled, the smaller shapes juggled, and a pentagonal prism turns out to be a great base for a cylinder tower.
Geometric Solids, Learning Resources £14.99