This test is not a test of biology, chemistry, physics, earth science, and other science you’ve learned in school – at least, not directly. You don't need to remember everything you’ve learned from those classes; instead, you need to know how to reason and solve problems scientifically.
The ACT Science typically contains three types of passages: Data Representation (usually 5 questions), Research Summaries (usually 6 questions), and Conflicting Viewpoints (usually 7 questions). They are not in any special order – typically you'll see three 5-question sections, three six-question sections, and one seven-question sections, but that hasn't been strictly true on some recent tests.
The biggest obstacle separating students from their target score is the limited time you're given to read the seven passages and answer forty questions. Thirty-five minutes is just not enough time to do all that work comfortably, so you will have to keep the pace up if you hope to finish the test.
Don't jump to the questions right away. First scan the figures, graphs, and tables to get a feel for the experiments or studies. This will give you an idea of what to focus on when you do read the passage. For example, a question may ask something like, “Based on Experiment 1...” or “According to Figure 1...” When you see this, go straight to the experiment or figure and find your answer.
ACT Science requires many of the same skills that ACT Reading does. The only major difference is that the Science section passages almost all relate to numbers or scientific processes or both. And the Science passages usually contain graphs and tables rather than paragraphs. Sometimes a question will require you to gather more information that isn't in the passage or figures. For example, you may be asked for the stopping distance of a train traveling at 65 mph, but the graph only shows speeds and stopping distances of 50, 60, and 70 mph. To answer the question, you have to find the point that would logically fall between 60 and 70 mph.
In this passage two or three people share their conflicting opinions on a topic and no visuals are provided. Because the conflicting viewpoints are strictly text-based, it’s essential that you read them in their entirety in order to answer the questions.
If you do decide to skip around, make sure you are still bubbling your answers into the corresponding numbers on the answer grid. You don’t want to lose points because you bubbled incorrectly!
Full-length practice tests are available in ACT practice books at local bookstores or at your local library. Find a quiet place where you can take the practice ACT, and clear off the table or desk. Try and eliminate any distractions and do the best you can to mimic your test-day environment. Keep a clock or timer in front of you so you can periodically check and see how you are doing. You may want to set the timer to go off every 6-7 minutes. Don't rush, but make sure you can move confidently from one passage to the next and answer ALL questions in the time allotted.