Question related 2 exams?

pls help me....my exams r goin on ......and tehy really sucked i got really less marks in my strongest subjects ....dunno wta shappening 2 me i know all the ansewrs bt i write evrythin wrong .......smetimes iread teh ques wrong .....,smtines i do 2+2=5 ....almost all teh exams i ve given have gone badly ...wat should i do 2 improve????????