Montessori Wooden REVERSIBLE Math Board with Number Cards 1-20 are perfect for young children who are learning addition and subtraction. Made from high-quality wood, these boards are durable and eco-friendly, making them a great choice for parents and teachers alike. Each cards features numbers 1 through 20, and the accompanying cards can be used for a variety of math activities. With these boards, children can practice addition and subtraction in a hands-on way, developing their math skills in a fun and interactive way. These boards are perfect for use in a Montessori-style classroom or at home, and are sure to become a favorite among both children and adults.