"Cramming tries to get a lot of information into short term memory just before the exams. It is a futile strategy when the material to be covered is wide ranging. What you need is strategies to store data in long term memory. It is very important not to worry about or even to attempt to cover and remember everything. It is very important not to overdo it. There is a limit to how long you can concentrate. For me the limit was about 2 hours. Make customised notes. Write down things you want to remember. Make no attempt to be comprehensive. Read these notes before the exams. Best of luck.