
An evaluation must be done and reviewing your lecture material to determine if it is too difficult or too easy should be one of the 1st things attempted.
Look inward and ask yourself if you are presenting the material in a positive and interesting way. It is important that you challenge the student. It is crucial that you haev planned your lecture and be prepared.
Another alternative is to engage the student by breaking the class up into work groups. This allows for students to interact and give opportunities for brainstorming.