Roller Digital Teaching Stamp: Adjustable numbers, smooth scrolling, Can efficiently and quickly print out less than 100 math problems.Clearly printed and can be used again and again. Repeatedly Used: Small and exquisite, easy to carry and can be reused after adding ink.Clearly printed and can be used again and again. Develop mathematical skills: Can rotate and adjust the column type, adjust 10 different queuing methods.Complete all addition/subtraction/multiplication/division numbers from 1-100.Fun lessons that make children enjoy learning more. Best Gifts: Roller Number Teaching Practice is learning and educational gift when children need to practice math problems, parents can prepare them quickly.Roller Digital Teaching Stamp for wonderful Christmas birthdays, Easter gifts, etc. Primary school students do one page a day to improve the speed and accuracy of oral arithmetic, cute convenient and practical.