Cuisenaire rods give students a hands-on elementary school way to learn elementary maths concepts, such as the four basic arithmetical operations and working with fractions. In the early 1950s, Caleb Gattegno popularised this set of coloured number rods created by the Belgian primary school teacher Georges Cuisenaire (1891-1976), who called the rods réglettes.
The educationalists Maria Montessori and Friedrich Froebel had used rods to represent numbers, but it was Cuisenaire who introduced their use to teachers across the world from the 1950s onwards. He published a book on their use in 1952 called Les nombres en couleurs. Cuisenaire, a violin player, taught music as well as arithmetic in the primary school in Thuin. He wondered why children found it easy and enjoyable to pick up a tune and yet found mathematics neither easy nor enjoyable. These comparisons with music and its representation led Cuisenaire to experiment in 1931 with a set of ten rods sawn out of wood, with lengths from 1 cm to 10 cm. He painted each length of rod a different colour and began to use these in his teaching of arithmetic. The invention remained almost unknown outside the village of Thuin for about 23 years, until Gattegno came to visit him and observe lessons in 1953. With Gattegno's help, the use of the rods for both mathematics and language teaching was developed and popularised in many countries around the world.
The Silent Way 
- to demonstrate most grammatical structures such as prepositions of place, comparatives & superlatives, determiners, tenses, adverbs of time, manner, etc.,
- to show sentence and word stress, rising and falling intonation and word groupings,
- to create a visual model of constructs, for example the English verb tense system 
- to represent physical objects: clocks, floor-plans, maps, people, animals, fruit, tools, etc. which can lead to the creation of stories told by the students as in this video.
Other coloured rods 
In her first school, and in schools since then, Maria Montessori used coloured rods in the classroom to teach concepts of both mathematics and length. This is possibly the first instance of coloured rods being used in the classroom for this purpose.
See also 
- Cuisenaire® Rods Come To America
- Teaching fractions with Cuisenaire rods
- Catherine Stern on sternmath.com