Talk to the teacher
Before taking any serious action, it is better to talk to the teacher, if you are having any issues. Make sure you talk to some of the other classmates too in order to find out whether you are the only one facing problem or are others also suffering because of the teacher. If the teacher is experienced, he/she will definitely change the methodology and find other ways of explaining things to you, which might work out.
Accept your responsibility
Even if the teacher is unable to explain things properly, it doesn’t necessarily mean that he/she is the only one at fault. You might have been unable to concentrate properly during the classes, which can be a reason behind your struggle. Stay alert during the entire session, which will definitely help in improving things a bit.
Get the administration involved
If you see things are getting out of control, it is better to get the administration involved. This way, you might get a new teacher, who has got better command on the subject and knows how to pass on knowledge to the students.
Talk to your parents
In case the administration doesn’t listen to you, it is better to get your parents involved in the matter. Ask your classmates to do that same in order to make sure that some necessary action is taken.
Find a tutor
You can always hire a tutor to get proper understanding on a particular subject, which is not taught well by one of your teachers. However, this will cost you extra money and time, so you will have to manage everything accordingly.
Change your class/school
The final resort should be changing your class or school. This is not easy, as you have to adjust to a new environment, so you should try and resolve things in a different manner.