The developmental milestones for kids in this age group sees a lot of rapid change from year-to-year that makes condensing it into a brief overview difficult. Kids start out growing use not only to using tools with increasing skill, but also a greater body awareness that, by the latter half of this age range grows into greater awareness of gender differences. As such, the mastery over self and tools and working until exhausted are some of the key identifiers of this age group. Sports also become more important as they help with the exploration of physicality and eventually being in a constant state of motion while awake by the end of this age range. The types of games tend to take these developments into account.
In terms of information and intellectual development, the younger end of this age range is still in the information gathering phase as they continue to commit facts to memory. It is not until the latter half of this age range that they begin to use logic, categorization, and deep though to better understand and use that knowledge. The child also starts to internalize physical lessons into mental ones as analogous structures. Conceptual frames, like time, are elusive for the 9-10 year-old crowd, but become easier to manage and use and can be applied to the worldviews of others. This growing awareness helps with the social developments of the child discussed below.
Kids begin this age range unwilling to do anything they find unpleasant, which includes chores and often being around the opposite sex. They can be responsible and carry out chores. Emotions have more sway over the first half of this age, but mellow out as reason develops. Friendships grow in importance, but it is not until the second half of this stage that relationship with parents begins to change. Group activities continue to become more important to the child and by the end of this age range, the desire to conform to peer pressure begins to develop as the drive to feel connected to a social fabric of shared interests grows. Interests grow more important and sharing is communicated as much by enthusiasm as it is dislikes, which may be more prominent than the former.