A lot of times it's due to a lack of time and self control. Parents can set a time to play the game by letting the sand out of the time sand clock, and the game ends after 30 minutes. Using an hourly glass timer to show the length of time is more intuitive to younger children, easier to understand, more pictorial, and can develop a child's sense of time. Use the sand watch clock to train children for a long time can get good results. Use the hour sand glass for two minutes to set the time for brushing teeth. When the sand is over for two minutes each time, the child will stop brushing teeth and gargle. In a word, parents can quantify time in various aspects of life, so that children can feel time more clearly and cultivate their own ability. That will make them become more independent in their life and do their own things more efficiently.