For a simple but effective maths-in-a-box starter set, the Magformers Basic 90 pack takes some beating.
 
It contains all the elements of the Basic 40 and curved sets, with some extra shapes thrown in too - being made up of 12 triangles, 20 squares, 6 isosceles triangles, 2 hexagons, 2 pentagons, 4 rectangles, 4 diamonds, 4 trapezoids, 4 triple rectangles, 4 cones, 4 cylinders (arches), 8 spheres, 8 quadrants, 8 sectors.
 
Children can make huge numbers of 2D nets and 3D solid structures, while exploring lots of different shape properties and developing mathematical language as they play.
 
And with a stackable storage container making it super easy to clear away and store your Magformers, it's a perfect classroom solution.