The first thing to do when teaching a frustrated student is to listen to, and acknowledge, their frustrations. Let him or her vent a little. If you're working with young children, they probably won't even realize or communicate that they are frustrated. Therefore, the first thing to do is say "you're very frustrated with learning ________ aren't you?" If you are in a group situation, take the student aside to talk to him or her about it so he or she doesn't become embarrassed.
One of the best things you can do when teaching frustrated students is to watch them one-on-one in academic action and observe every little detail when they think, write, and speak. Often, students are lacking very particular, previous basic skills. By watching them work, you can identify where they are going wrong and notice common patterns. For instance, I have tutored many algebra students whose frustration stemmed from an inability to deal with negative numbers. Once this problem was corrected, the rest of the material became much easier for them to interpret. Isolating and rehearsing small, specific skills can open a fast-track door to understanding.
When dealing with a frustrated student, it is important to give positive reinforcement for small triumphs. Don't let them get caught in an "all" or "nothing" assessment of their capabilities. Grades and teacher praise in class do not give them a detailed picture of how they are doing. This causes them to jump to the conclusion that "they just can't get it." Use meaningful praise that not only tells them they did a good job, but gives feedback as to their understanding. For instance, you could say "Wow, _______ was a great pick, your word choice is really improving."
Don't let a frustrated students fool you or themselves into thinking that they know more than they do. Many times, a student will have "moved on" months earlier (without realizing it) when they didn't get a specific skill. If a student is struggling, they might resist going back to basic techniques, but you should test them on, and watch out for, these skills anyway.
When teaching a frustrated student, you should strive to be his or her guide and always make a point of talking as though the two of you are a team tackling the problem together. Frustrated students feel lost and left-behind and need someone "at their side" instead of looking down to them.
As the guide, you should encourage the student to trust you. He or she may be frustrated because of inadequate or mismatched teaching styles and be ready to shut you out before you even begin explaining the material. Reassure him or her that you will always be able to give another explanation or example if he or she doesn't understand the first ones. The goal is to reassure the frustrated student and develop his or her patience so that he or she can calmly and openly listen to you.
Make sure to explain "why" and "how" for absolutely everything. Explain why you are working together, how it will help, why certain techniques are important, why he or she will need to know certain concepts for life or college. A student that is frustrated needs to feel "in the loop." So, never forget to include age appropriate and child-specific "whys."
Try new teaching techniques. Switch from verbal to visual explanations or vise versa. You might also try an interactive game. The student might be stuck in a rut of teacher, parent, or self-explanation that isn't going anywhere. Therefore, do something that will shed new light on the material.
Finally, make sure you admit your own mistakes. If you gloss over wrong or inaccurate things that you have said because you are afraid of looking fallible, it will contribute to the student's frustration and confusion and lessen his or her trust in you. So briefly apologize (yes, apologize, it is important for maintaining trust and partnership). Give a visual and start over by saying something like "We're going to wipe clean what I just said."