Begin to help your daughter improve her test-taking skills by analyzing where she is having problems. If she has tests from last year, you might look them over together. Consider these questions: How well does she know the subject matter? Is she familiar with the test format? Does she have poor skills in answering test questions, or does she suffer from test anxiety?
You may find it helpful to use a study-skills book with your daughter in finding ways to improve her test-taking skills. If your daughter's problem is not knowing the material, work on teaching her how to study for tests. Do point out that most teachers explain exactly what will be covered on tests. If she doesn't know how to handle different test formats or how to answer different types of questions, work with her on practice tests similar to those that she will take at school. As your daughter begins to learn how to handle tests, her confidence should increase and any test anxiety that she has will decrease.
Since most standardized tests tend to be multiple choice, you should teach your daughter the following tricks: (1) Think of the answer to a question before looking for it on the test. (2) Eliminate answers that don't form grammatically correct sentences. (3) Choose one of two answers if they are very similar except for one or two words.
As far as your daughter's math skills go, determine if she any specific weaknesses. Then use your teaching skills to improve these areas.