About this item[Teaching Stamps for Kids]: 4PCS smart math roller stamps,: Addition +Subtraction + Multiplication+ Division, 4PCS bottles of ink[Math Practice Stamp]:The math stamps as fun as toys, make learning fun and exciting, Increase children's interest in learning ! Suitable for students to practice, Parent guidance, Teacher teaching,stationery and 1st grade teaching supplies.[Easy To Use] :Efficient And Fast ，The math questions can appear in front of you by scrolling the kiddo stamp.[Rotary Adjustment Design]:10 different queue modes can be adjusted, Satisfy all addition and subtraction within numbers 1-100, Develop children's logical calculation ability.[ Refill Pack]: Durable，Equipped with 4 Free refills ink, Open the oil cap and drop 5-6 drops at once,the kiddo stamp can be reused.