This 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 Fraction Stax Set is 4-1/2" tall. Set is designed for students in second to sixth-grade and children ages 7 to 12.