Good answers so far. A friend of mine asked me several months ago to help her with her daughters math tests, she knows I am a math person. She could not understand why her daughter did well on math assignments and had a lot of trouble on the tests. Every answer she got wrong was because she did not read the problem well. If her homework assignments say list these series of number lowest to highest she always did them perfectly, but then her test asked list them highest to lowest, and she chose the answer that was like her homework, lowestto highest. Her mom thought she was not ale to do it in the reverse or order, but that was not the case it all, it was simply her daughter made an assumption about the directions, rather than reading them. She did this over and over again on different types of problems. Look over your test and see if that is what you possibly have been doing. It is extremely important on tests to read questions word for word, you can not speed through it. Some people can read in blocks, they are very fast readers, which is great, but they fill in words without actually reading all the words.
Is the test multiple choice? Or, show your work?