GED science practice test, with each answer explained
Eight science questions written by us, from experiments to energy, each with its explanation. The real test lasts 90 minutes, with a calculator.
1 of 8
A student gives three groups of the same plant 0 g, 5 g and 10 g of fertilizer and measures their height after a month. What is the independent variable?
Practice questions written by us from the published test topics. They are not real GED or HiSET questions, and this score does not predict an official score.
Prepared by Radif Partners · Method · fees and rules read on ged.com and hiset.org on October 22, 2026
The GED science test lasts 90 minutes, including 2 minutes of instructions and final review, with no break. ged.com lists three skills rather than a list of facts to memorize: reading for meaning in science, designing and interpreting science experiments, and using numbers and graphics in science. You get an on-screen calculator and a calculator reference sheet, and at a test center you may bring your own TI-30XS. Questions are multiple choice, fill in the blank, drag and drop, select an area and drop-down. Science passes at 145 like every subject, and from 175 a score can be worth up to 3 college credits in science, depending on the college. The eight questions above are ours: two on a fertilizer experiment (what the variable is, which group is the control), an average speed, boiling water on a mountain, photosynthesis, a cross between two brown-eyed parents, whether an object floats from its density, and the energy change in a flashlight. Most of the test gives you the information in a short text, a table or a graph; the work is reading it correctly and doing a small calculation.
The three skills, with what they look like
Reading for meaning: a paragraph explains how vaccines train the immune system, and the question asks which statement the paragraph supports. Designing and interpreting experiments: you are told what a student changed and what she measured, and you must name the variable, the control group or the flaw in the design. Using numbers and graphics: a table gives temperatures over a week and you compute the mean, or a graph shows two lines and you say where they cross.
The vocabulary of an experiment
The independent variable is what the experimenter changes on purpose. The dependent variable is what she measures. The control group gets no treatment, so that results can be compared against it. Constants are everything kept the same: same plant, same soil, same light. A hypothesis is a testable prediction, often written as “if… then…”. Half of the experiment questions on the test come down to sorting these five words correctly.
Your science score against 145
Your GED result
1 to retake
| Math | 150 · Pass |
| Language arts (RLA) | 146 · Pass |
| Science | 150 · Pass |
| Social studies | 140 · 5 points short |
An extra worked example
A table shows a plant’s height after 1, 2, 3 and 4 weeks: 4, 7, 10 and 13 cm. How tall will it probably be after 6 weeks if the trend continues? It grows 3 cm a week, so 13 + 3 + 3 = 19 cm. The phrase “if the trend continues” matters: the test may ask, in another question, why that prediction could be wrong, for instance because plants stop growing at some height.
Scores and credit
Science is scored on its own and passes at 145. From 165 it is College Ready; from 175, ged.com says it can be worth up to 3 college credits in science, as for math and social studies. Each college decides whether it accepts that credit, so ask the admissions office of the one you have in mind.
How to prepare
Practice on graphs and tables more than on textbooks. Each day, take one chart from a newspaper or a science news site and write two sentences: what it shows, and what it does not prove. Rework the math skills science uses most, averages and percentages, with the math questions. If you test online, a green GED Ready science score is required within 60 days before the test; the GED Ready page explains the price and the three result bands.
Reading a graph in four steps
First read the title, which says what the graph is about. Then read each axis and its unit: days or weeks, degrees or percent. Then read the key, if there is more than one line or bar. Only then read the question. Test takers who skip the axes often answer in the wrong unit, or read a cumulative total as a weekly figure. On the real test, the four steps take less than half a minute and save points on several questions in a row.
When to schedule science
You do not have to take the four subjects in a set order. Science is shorter than language arts and uses the same reading skills, so it suits a test taker who reads comfortably. If graphs worry you, take math first: the same arithmetic then feels familiar on the science test. Our GED timeline calculator shows how the order and your study weeks change the date you can finish.