Arithmetic digit board for children's practice.

Description:1. Rotate the gear in one second to change the question, and it is easy to use, and the question is easy to rotate.2. The upper gear changes the number in this area, and rotate the lower gear to change the number in this area.3. Slide the paddle to switch operation symbols, double the number of questions \ operation symbols freely choose, nearly 10,000 permutations and combinations.4. Paperless answering questions, saving paper and protecting the forest, parental counseling artifact, interesting teaching, let children fall in love with mathematics.5. Practice once a day for three weeks to improve the child's verbal and mental arithmetic ability;  answer the test faster, save answering time, and achieve corner overtaking. Specification:New and high qualityProduct name: Arithmetic writing boardCategory: calculation exercise suppliesmaterial: plasticColor: as shown in the figureSize: 13.2 * 4.4cmPackage Included：1PC Note:Please refer to the measurement.  A tiny measuring e