Some children seem to enjoy arguing; they criticize your decisions, challenge your answers, and question your directions. Children argue not just because they have a gripe, but also because of what they hope to gain from their arguing, namely attention and power.
If you have an argumentative student, you can find yourself spending considerable time debating, justifying, and explaining. That might divert you from your lessons and encourage the arguer's classmates to engage in similar behavior.
The problem is not that a student is challenging a teacher. An important goal of education, after all, is to help students become independent thinkers. The problem is a child who challenges her teachers in an inappropriate manner. Your goal in working with an argumentative student, therefore, is not to stifle the expression of opinions, but to help her learn to convey those opinions in an appropriate and respectful manner.
WHAT YOU CAN DO
Don't take the bait. The argumentative student wants to elicit a response from you, either by engaging you in debate or by upsetting you. Neither of those reactions, therefore, will change her behavior. Respond instead in a matter-of-fact manner, perhaps saying something like "Sarah, I'm sorry you feel that way." Then return to what you were doing without giving her an audience.
Give a brief lesson in communication skills. The first few times the student argues with you, help her see that she can make her point in another way. You might consider saying something like, "Tonya, you don't need to argue or speak disrespectfully to get your point across. If you state it in a pleasant, respectful manner, you have a better chance of being heard." You might suggest an alternative way to state her opinion. Let her know privately that her arguing can be unpleasant to listen to and that other students might avoid her if she continues to express herself in that way.
Help the student become more aware when she is arguing. Arguing could be so second nature to the student that she doesn't even realize she's doing it. Try establishing a private signal you can use to cue her when she is being argumentative. The signal might be as simple as getting her attention and touching your lips with your finger.
Encourage the student to put her argument in writing. Ask her to write down her thoughts on paper and leave them on your desk. Tell her you will get back to her within a day or two. Make sure to follow up with the student even if you think her point is without merit.
Make time during the day to hear her argument. Tell the student you are interested in hearing her concerns, but that class time is not the right time to do so. Ask her to see you either before or after school to discuss the issue. Let her know that you will listen attentively to her argument as long as she speaks in a calm and respectful manner, and that you expect her to extend that same courtesy to you. You might want to set a time limit for the discussion.