Hi Thanvitha, It's very exciting to hear that you are going for National level Mathematics Olympiad  in class 9.

As for national national level Maths Olympiad you will practise for IOQM (Indian Olympiad Qualifier  in Mathematics ). This exam is conducted by Mathematics Teachers’ Association (India) [MTA(I)] in collaboration with HBCSE (under NBHM). the exam duration is 3 hours with total of 30 questions. Question asked is of type integer-type-answer (00 - 99). Total marks is 100

Click here to download practice sets of IOQM and know some more details about IOQM