The best thing you can do to improve your grades is focus and pay attention when the information is first presented to you. It's easy to lose focus when your teacher is going on and on about something that's  not interesting, but you should not tune them out. Really listen to what they're saying and keep yourself engaged by asking questions and taking notes. . It might seem silly, but notes are actually a great way to help you improve your grades. Good notes are like a road map, when you go to study later on. They'll also show your teachers that you're serious about doing better in your classes. You don't have to write down everything your teacher says: just get down the basics. You know when you tell your parents about what happened to you during the day? That's how you should take notes. Just get the broad strokes, with the really important things written with greater detail.  If you know something is confusing to you or seems really complex, write that down too! Even if you don't understand what your teacher is saying, you'll have a note to yourself that you need to look that up and get more information later. Write out your notes by hand, instead of on a computer. You will have an easier time remembering them this way. When you don't understand a concept or fact that your teachers talks about in lecture or that you encounter in your text books, don't be afraid to ask! Smart people don't just know everything instantly...they're curious enough to ask and find out when they don't know something.  If you're nervous about asking in front of everyone else, you can also talk to your teacher outside of class time and ask about getting some extra help or explanation. You also shouldn't feel like your teacher would be angry about you not understanding. Teachers are happy when you're interested enough and invested enough to ask for help. If your teacher doesn't explain it in a way that you can understand or if you still feel uncomfortable, try going on the Internet to find a new explanation. You can often find...

How would you rephrase that briefly using Indonesian?
Memperhatikan di kelas. Mencatat. Bertanya jika Anda tidak memahami. Melihat kembali silabus Anda. Snack sepanjang hari. Cobalah cari cara untuk berhasil dengan gaya belajar.