Vincent and Tara are making triangles with the class construction set. They have a pile of strips of different lengths. How many different triangles can they make?
Age 5 to 11 Challenge Level:
Full Screen Version
Click on 'Rods', to choose a Cuisenaire rod and then drag it onto the squared background. More rods can be added in a similar way and aligned as you wish. A rod can be rotated by $90^\circ$ by clicking any key whilst dragging. The background squares can be altered (for example increasing/decreasing their size) using the 'View' menu. For a version without background squares, please see
You could use this environment for all sorts of purposes - perhaps to explore addition and subtraction, factors and multiples or ideas about fractions.
For more ideas, look at the Notes section, or go to this page where there is a collection of Cuisenaire problems.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice.