Simon Gregg, Toulouse, France
Cuisenaire rods, invented by the Belgian teacher Georges Cuisenaire in 1931, are one of the great manipulatives we use in the classroom so that children can see and handle numbers as objects, and explore the properties of numbers physically and visually. There are two examples of their use in this video: using the rods to represent the factors of a number, and using them to investigate a particular case of the difference of two squares.
Here’s a fascinating video of Caleb Gattegno using Cuisenaire rods with young children. The nrich Cuisenaire environment is a easy way to try things out online, and to record what has been done with physical Cuisenaire rods. The nrich site has a lot of other activities that use the rods too.
See my blog post for a more open-ended way that I’ve used the rods to explore visual patterns.