20 Packs Number Line Dry Erase Boards Cards, Double Sided Writable and Erasable Board Card Featuring -10-10 Number Line On One Side 0-20 On The Other, Classroom Must Haves Boards for Students

20 Packs Number Line Boards：20 Pcs number line boards are sufficient to meet the needs of classroom grouping, family interaction or multiple scenarios, making math learning no longer boring. The number line board visualizes abstract mathematics, helping children quickly understand numerical relationships and making addition and subtraction exercises more efficient. Double-sided design: The front side of each card has 0-20 (basic operations) and the back side has -10 to 10 (negative number enlightenment), making it easy to deal with mathematical concepts, which can help students learn and reiterating essential math skills. Erasable and reusable: High-gloss coating surface, smooth writing without jamming, easy to use with ordinary whiteboard pen (pen needs to be purchased separately), wipe clean with a wet cloth, no residue or traces, reusable, save paper and be more environmentally friendly. Portable storage: Each board measures about 3.4” x 10.4”, making it very convenient to carry around, suitable for school bags, desk drawers, home tutoring, classroom practice, or learning math anytime while traveling. Designed for 4-6 years old: A math tool suitable for both home and school. A must-have for kindergarten to first grade addition and subtraction enlightenment. Combined with school courses or family tutoring, the effect is doubled.