Siri can adjust the volume for you, hands-free. Just say "Hey Siri, turn it up" or "Hey Siri, make it softer."
Siri can do a lot of things and the list continues to grow. Find out what she can do by asking! Day "Hey Siri: what can you do?" and she'll give you a list.
Siri is good at math. Simply put your math question into words and she will solve it. Yes, this is "Word Problems." You probably thought you were through with them.
Siri can adjust screen brightness! Easier than doing it by hand, and after adjusting the brightness, Siri leaves a slider for you to play with just in case.