First you look that the way you attempt the paper. Then make a time table & give proper time to every subject.
Read once slowly & with deep concentration to make you under stand.
Make habit that read your lesson one day before & then when you come back from school, must read what ever you read on that day. In this way you remember & your concept will be very clear.
All the year you are a student not only when your exams are on the head only.