Hi, Have you talked to a counselor at your school? Alternatively you might talk to your math and science teachers and seek their advice.

For general information, study help and practice problems in math and science, here are some resources on Education.com you may also find helpful for sharpening your skills:

http://www.education.com/topic/study-help/
http://www.education.com/topic/test-prep/
http://www.education.com/worksheets/high-school/
http://www.education.com/activity/high-school/

Consider also talking to local tutors who can work with you in person and help identify specific areas that need improvement. All the best to you in achieving your academic goals, and thank you for asking!

High School Success and College Application is a book that will likely help you in studying as well as many other areas of high school. Grades are important, and it's also important to take a big picture view as you go through the rest of high school.

In the book, the author explains key points and fundamental strategies regarding class selection, grade point average, test skills, attitude, extracurricular activities, honors, awards, recommendation letters, essays, interviews, and college applications.