Digital Teaching Stamp Roller Adjustable numbers, gently scrolling, Can efficiently and quickly print out less than 100 math problems. A fun and meaningful gift for your child or your friend's child Teaching Stamp Reusable Small and exquisite, easy to carry, can add ink for reuse. The imprint is clear, and it dries and does not fade after printing. Product includes digital teaching stamp. Learning and Educatinonal Gift Keep the kids busy and get yourself a moment of quiet when they need it. So, it's a great gift for our kids and even for parents. Math Skill DevelopmentRotate and adjust the column type, can adjust 10 different queue methods. Satisfy all addition/subtraction/Multiplication/Divide numbers from 1-100. Develop children's logical calculation ability.