Description

This is an interesting tool that can practice your calculation ability. You need to select a number from the flying balloon within 20 seconds of the countdown, and fill in the appropriate number in the remaining box. If the answer is verified to be correct, continue to the next question, and add one to the total score. If you are wrong or over 20 seconds, the practice game is over. In this process, you need to calculate quickly and accurately. You can check your own historical answers, analyze your own wrong questions, and improve your calculation ability.