In the late 1940s, Catherine Stern of New York City introduced this set of blocks and boards for teaching basic counting, addition, and subtraction. By the mid-1950s, she was selling it for use in primary schools as well. After the launch of Sputnik, Stern's ideas received new attention in journals for arithmetic teachers.

 

Many educational reforms brought together students, teachers, and university professors. This photograph shows an arithmetic class in Illinois. Students in the front are using Cuisenaire rods. Behind them, over the blackboard, is a number line. Charts showing a line with positive and negative whole numbers written on it had been used in American mathematics teaching from the 1880s, but did not become common until the reform movements of the 1950s and 1960s.

 

The Belgian educator Georges Cuisenaire introduced a set of rods for teaching young children arithmetic in the early 1950s. Publicized by the Egyptian-born entrepreneur Caleb Gattegno, the rods sold widely in the United States in conjunction with new mathematics curricula.