* Teach children to know -100
* Chinese and English dual model
* Know the meaning of the interval
* Guess the number can learn the concept of digital size
* Chance - can increase or decrease the number of guesses
* Special function in the eyes
* Teach children to know -100
* Chinese and English dual model
* Know the meaning of the interval
* Guess the number can learn the concept of digital size
* Chance - can increase or decrease the number of guesses
* Special function in the eyes