The answer to your question can be found in chapter 4. Elie tries to protect his father from being beaten by teaching him how to march properly. This incident comes in the aftermath of Elie being hesitant to give up his gold dental crown to Franek, who is a foreman in the electrical warehouse. Franek is looking for a way to punish Elie, and he knows that the best possible way to do this is to hurt Elie’s father.
Having never done military service, Elie’s father is not adept at marching and has a hard time marching in step with his fellow prisoners. This gives Franek the excuse that he needs to beat him up on a daily basis. In order to nullify this excuse, Elie decides to “give [his] father lessons in marching in step.” These practice sessions took place outside their block, and as Elie commanded “left” or “right,” his father would try to follow the tempo.
During these lessons, they endured taunts from their fellow inmates, with them asking Elie whether his father was paying him for the lessons with bread rations.
Unfortunately, Elie’s father proved unable to become a competent marcher, and Elie’s attempt to protect his father proves to be a failure. Eventually, Elie makes things better for his father by giving up his crown. This was a significant sacrifice, especially given that the crown was removed “with the help of a rusty spoon.”