100 exersicers math exercises roller stamp built-in two rollers, a single roller has 10 numbers, by rotating the roller to make the numbers match each other, generate different math exercises, suitable for primary school students math practice use. This product can produce addition, subtraction, multiplication, division, fill in the blank, etc., each product can generate 100 practice questions, and a single refueling stamp more than 1,000 times, printing surface continued ink stamp more than 10,000 times. The external material of the stamp is ABS environmental protection material, which has the advantages of small odor, wear resistance, corrosion resistance, not easy to burn, etc., and the user has more sense of security. The internal material is Simple flash foam pad, stable performance, fine surface, uniform opening, moderate inking time, and good repeated oil filling performance. Clear exposure, no white edge, high surface melt layer strength, durable wear, upgrade melt layer thickness and density make the seal surface more black, brighter, no slow penetration leakage ink, seal effect is extraordinary.1000 exersicers math exercises roller stamp built-in three rollers, a single roller has 10 numbers, by rotating the roller to make the numbers match each other, generate different math exercises, suitable for primary school students math practice use. This product can produce addition, subtraction, multiplication, division, fill in the blank, etc., each product can generate 1000 practice questions, and a single refueling stamp more than 1,000 times, printing surface continued ink stamp more than 10,000 times.Special inks: water-based ink Cover design: open when not in use, close when not in use, to avoid the loss of the cover and printing oil volatilization. Oil injection: stamp surface Shell size:65mm*31mm*48mm Imprint size:23mm Shell material: ABS environmental protection material,simple flash foam. Suitable for: 6-10 years old