In Chapter 10, Atticus reluctantly shoots and kills a rabid dog that is staggering down the main road of Maycomb. Atticus's expert marksmanship shocks his children, who previously felt that their father was old and untalented. Jem and Scout are in awe of their father after witnessing him shoot the dog. Following the event, Miss Maudie explains to the children that Atticus is a humble, civil man who never brags about his talent. Jem and Scout learn a valuable lesson by the end of the chapter. They learn the importance of humility, civility, and courage by witnessing Atticus's actions. The children also learn not to judge a person simply based on their appearance. Despite the fact that Atticus looks old, he is capable of extraordinary things. Atticus is also affected throughout Chapter 10. Although he does not want to kill the dog, Heck Tate gives him the gun. Atticus has no choice but to shoot the rabid dog and protect the community. Atticus's actions parallel his future defense of Tom Robinson and prepare him to confront Maycomb's ugly racism.
Atticus is seen by somewhat weak and not overtly masculine by his children. They think his age and occupation are boring. Scout is coming to an age where she wants an elevated sense of self within the community, but realizes her father does not garner the recognition he could if he wanted to. Both children see his peaceful nature as a weakness.
The showdown with the rabid dog changes their perception of their father. Jem learns that his father's nickname was "One-Shot Finch" and this is a source of enormous pride to the boy. Atticus's ability to calmly handle the situation with the rabid dog shows the children that their father is not afraid, he merely feels no need for senseless shows of masculinity. He is strong and forceful when the situation calls for it, and the children grow to respect this quality.
Scout realizes that his peaceful nature shows that "he's civilized in his heart", not weak in character. The children see him as a man, not just as a dad.