Montessori Teen Board Set Exploration of the numbers 11-19 and their sequence is possible with this beautiful hardwood set. Consists of a wooden box with lid containing two teen boards with the numeral 10 printed on nine of the number slots, and 9 wooden tablets with the numerals 1-9 printed on them that slide over the zero on the number slot to create the written teen symbol. Teen beads are sold separately. See item number M6319