The ACT science reasoning test frequently intimidates students, because they find science difficult. The first thing to remember when taking this test is that you need very little prior knowledge of science to do well. It is basically a reading test, just with scientific material. If you can read a short scientific passage, find information in a table, follow a graph, and remember the scientific method, you should be able to do reasonably well on the ACT science reasoning test.
The first strategy to employ is recognizing the different formats and subjects of the passages in the science reasoning test and learning which ones are easiest for you to understand. If you generally understand biology better than physics, do the biology passage(s) first. If you find passages with lots of charts, graphs, figures, and/or tables to be easier to understand than lengthy reading passages, do those first.
Second, remember to keep things simple. While reading these passages, you will inevitably encounter new words and concepts you don’t understand. The testmakers do that on purpose to intimidate you; don’t allow yourself to be intimidated. When you read a word you don’t know, just keep reading. If you read about a concept you don’t understand, don’t spend time trying to decipher it. Read the questions and then search for key words in the passage (or in charts, graphs, tables, etc.). Don’t over think any questions; although difficult concepts may appear in the passages, you will find that the answer is usually more simple than you would think.
Also, keep in mind that the first few questions following each passage tend to be easier, basic fact type questions. These frequently can be answered by locating information on a table, graph, or chart. The later questions for a passage tend to be questions which will require you to make an inference or extrapolate; these are typically more difficult.
Answer the easy questions (keeping in mind that difficulty is always relative) first because you are more likely to get them correct, and if you find yourself spending quite a bit of time on a difficult question, guess on it and move. This way, you will have enough time to get to all of the easier questions. If you have time left over at the end of the test, go back and ponder the difficult questions.
One last valuable strategy: practice, practice, practice. The more you are exposed to this test, the easier it will become. Practice also allows you to learn from your mistakes, so pay close attention to the questions you are missing so that you can learn to get these correct.