Help young math students understand and apply basic addition and subtraction using these convenient dry erase boards with 0 – 10 and 0 – 20 number lines.Our handy and compact number line dry erase boards give students endless practice opportunities using number lines to perform simple addition and subtraction problems. They're affordably priced for supplying your entire class. Convenient Dry Erase Format: These specially formatted number line dry erase boards save the time and hassle of repeatedly drawing number lines on paper for math instruction and practice. Environmentally friendly, dry erase technology minimizes paper waste. Two-Sided Usefulness: With a 0 – 10 number line on one side and 0 – 20 on the other, addition and subtraction instruction can start with one-digit numbers and be developed to two digits as the basic concept is mastered. Compact and Sturdy: These preprinted dry erase boards are small enough to store easily with your teaching supplies or in student desks. Collect them later and use them year after year. Affordable: With Really Good Stuff's already low price, plus volume discounts for this item, you can afford to equip each of your students with one of these important learning tools while teaching simple addition and subtraction.Enhance your students' understanding of numbers, as well as simple addition and subtraction, with these convenient, environmentally friendly, number line dry erase boards. Grades: Pre-K – 2 Size: 12" x 4" (6 boards per set)