Parts List: 2Pcs Set 1?Á Addition Teaching Stamp Roller 1?Á Subtraction Teaching Stamp Roller 2 ?ÁBottles of printing oil (with 5ml of ink) 2 x Storage boxes or 4Pcs Set 1?Á Addition Teaching Stamp Roller 1?Á Subtraction Teaching Stamp Roller 1?Á Multiplication Teaching Stamp Roller 1 ?ÁDivision Teaching Stamp Roller 4 ?ÁBottles of printing oil (with 5ml of ink) 4 x Storage boxes Description: This digital teaching stamp roller with random math exercise is specially designed for preschool or primary children to exercise maths at home easily. Key Point: Mathematics Skill Development: Multiplication, additions, subtraction and division exercise in combination. Numbers from 1-100. Develop children's logical and calculation ability. Efficient and Convenient: The digital teaching stamp roller is easy to use, gently rolling can print math problems efficiently and quickly. Specification Name: Digital Teaching Stamp Material: PVC Teaching Stamp Roller Size: 44?Á30?Á48mm/1.73?Á1.18 ?Á1.88in Stamp: 20?Á4mm/0.78?Á0.15in Product Category: Stamp Feature: Rolling Wheel Suitable for Ages: 3+ Style(Optional): 4Pcs Set, 2Pcs Set Note: 1.There may be slight differences between the picture and the actual color of the commodity. We will try our best to show you the exact color 2.Please allow slight dimension difference due to manual measurement.