Mathematical exercise rolling seal: gently rolling, fast and efficient printing of mathematical problems. 2 Blue 2 Pink includes addition, subtraction, multiplication, and division. Give your child an interesting and meaningful gift. Family learning: it can be set to 10 different permutations to meet all the numbers in the 1-100 algorithm. It is suitable for students' practice, parents' guidance and teachers' teaching. In order to avoid repetition, the permutation of every 10 math problems needs to be changed. Clean and tidy: the color will not fade after drying, clean and tidy, and the printing is clear. Interesting math supplies: small and light. Cartoon color is the perfect choice for children. It is as interesting as a toy, making learning fun and exciting, and increasing children's interest in learning! Reusable: Homeschool uses 4 bottles of ink to practice rolling stamps. It can be reused after adding ink. Material: Plastic colour: As shown Package Contents: 4 x Roller Stamp 4 x ink Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.