Buy Montessori Trinomial Cube Two sets of ten small wooden rods divided into units by alternating colors of red and blue. The rods are constant in height and width (1cm) while they graduated in length from 2.5cm to 25cm. The rods are presented in a wooden box that includes one set of wooden number tiles 1-10. Similar to the Large Number Rods. But, this small number rods that comes in a set of 2 is used for addition and subtraction. • Recommended Ages: 4 years and up Buy now: https://kidadvance.com/small-numerical-rods.html