There are two very important ingredients to success:
1. A focus mind
2. The right tools
The first one can only be determined by you. The other can be gotten when you make the best use of the information available to you.
By extension, these two important ingredients will most assuredly guarantee you success in your mathematics examinations:
1. A focus mind
2. A good textbook
One good textbook is called "Simplified Mathematics DVD". It's an audio-visual textbook that has been prepared to meet the requirements of the mathematics syllabus at ordinary level (WASSCE, NECO, IGCSE and UTME). It is also a good foundation for Advanced level students and undergraduates offering a mathematics-related course. The topics, about 19, are comprehensive, well-explained and simplified.
Here's a preview:

https://www.youtube.com/watch?v=RhYVT0rTh8w

To order your copy, send an email to tutorialngr@gmail.com