Practice addition, subtraction, and multiplication using an open number line! This flexible workspace allows you to explore number relationships, estimation, measurement, and more. The open number line has a write-on/wipe-off surface for versatile number modeling and built-in storage for the included linking blocks and dry-erase marker. It comes with 25 red and 25 white linking blocks to aid in visualizing numbers, grouping strategies, and more. 52 pieces. Ages 5+