The Long Red Rods (also just called the Long Rods) material consists of ten wooden rods each measuring 2.5 cm (about 1") square in cross section, and ranging in length from 10 cm to 100 cm (about 4" to 40"). The material is designed to help students differentiate between different lengths, and understand that pieces of one length can be broken down into smaller components. For example, the 10 cm rod and the 30 cm rod together are the same length as the 40 cm rod. Each piece is finished in bright red with a protective clear-coat to resist chipping. The rods fit comfortably on our Large Activity Mat, and can be neatly stored away in the Rack for Rods (each sold separately).