<p>With the Teen Boards, the child explores the numbers 11-19. With the Ten Boards, the child explores the numbers 11-99. The child puts together ten bars and colored beads bars to create teen quantities, learns the symbols for 11-19 and associates the quality and symbol. The teen boards and 9 wooden cards with the numerals 1-9 printed on them. (For age 3-6)</p>