Pop bubbles on the number line to learn simple addition, subtraction, counting, skip counting and number properties with this durable "pop and learn" bubble board. The double-sided board features a number line with 0-20 printed on the front and blank bubbles on the back. Learn the concept of number lines with simple addition, subtraction, counting, skip counting and number properties. Interactive bubble board with 21 pop bubbles. Includes numbers 0-20 on a number line and blank bubbles on the reverse. Engaging for all children. For ages 5+. Age: 5 years/Grade K