[Mathematical exercise rolling stamp] You will receive 2 mathematical exercise rolling stamps, and fill in the blank with addition and subtraction within 100. This is an interesting and meaningful gift for your children or friends' children! [Reusable] There are 2 bottles of ink on the stamps of primary school teachers. You can add ink for reuse. The color will not fade after drying, and it is not easy to get dirty. [Easy to carry] The size of the mathematical cylinder stamp is 1.7 x 1.2 x 1.89 inches, which is small and delicate and easy to carry. It can be put in the stationery bag or pocket at any time. [Rotation design] There are 10 different queue modes in the mathematical exercise chapter, which can be adjusted. By gently scrolling, you can print less than 100 math problems efficiently and quickly. Cultivate children's logical calculation ability. [Efficient and fast] You can quickly prepare math problems for children . Just scroll through the math game and you can quickly complete the test. color:As shown Material:plastic Package Contents: 2 x stamp 2 x ink Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.