This Fraction Stax hands-on learning tool is great for teaching fractional relationships. The set includes 51 plastic stacking pieces that represent one whole, halves, thirds, fourths, fifths, sixths, eighths, tenths, and twelfths. One nine-peg base measuring 14" x 2 3/4" is provided and a teacher’s guide. The "whole" stax is 4 1/2" tall. Grades 2 - 6 / Ages 7 - 11.