DIGITAL TEACHING STAMP ROLLER: This math stamp roller features 4 operation styles—addition, subtraction, multiplication, and division. Simply roll to generate math problems efficiently and quickly, ideal for practicing calculations up to 100. REUSABLE & ENVIRONMENTALLY FRIENDLY MATERIALS: Made from durable PVC with precision engraving for clear, consistent impressions. Uses quick-drying, acid-free, lignin-free, oil-based ink that is safe for children. Suitable for both classroom and home use. ADJUSTABLE DESIGN: The Math Practice Number Rolling Stamp includes 10 number wheels, allowing you to easily customize math problems with a simple turn of the roller. Eliminates the need for handwritten equations, saving time on lesson preparation. PORTABLE SIZE: Compact and lightweight design comes with a protective storage box for easy transport. Refillable ink roller ensures long-term use. MAKE LEARNING MATH FUN: Helps develop children's logical thinking and improves mental calculation speed and accuracy. A practical and engaging educational tool, ideal as a gift for holidays such as birthdays, Christmas, Halloween, Thanksgiving, and New Year.