![Marbles in a box](/sites/default/files/styles/medium/public/thumbnails/content-03-02-six2-icon.gif?itok=8LI6k1CK)
problem
Marbles in a box
How many winning lines can you make in a three-dimensional version of noughts and crosses?
![Marbles In A Box Poster](/sites/default/files/styles/medium/public/thumbnails/content-id-6362-icon.png?itok=2KwvaziW)
![Nine Colours](/sites/default/files/styles/medium/public/thumbnails/content-01-04-six1-icon.png?itok=93zBgzQG)
problem
Nine Colours
Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?
![Triangles to Tetrahedra](/sites/default/files/styles/medium/public/thumbnails/content-03-02-penta4-icon.jpg?itok=mI3T5eVI)
problem
Triangles to Tetrahedra
Imagine you have an unlimited number of four types of triangle. How many different tetrahedra can you make?
![Nine Colours Poster](/sites/default/files/styles/medium/public/thumbnails/content-id-7207-icon.png?itok=bhbkRIdY)
![Tet-Trouble](/sites/default/files/styles/medium/public/thumbnails/content-98-05-six4-icon.png?itok=tMjJccb0)
problem
Tet-Trouble
Is it possible to have a tetrahedron whose six edges have lengths 10, 20, 30, 40, 50 and 60 units?
Image
![3D Shapes STEM footer 3D Shapes STEM footer](/sites/default/files/styles/large/public/thumbnails/content-id-13472-STEMlogo.png?itok=mefN5jyE)
You may also be interested in this collection of activities from the STEM Learning website, that complement the NRICH activities above.