Pick grade 5, grade 8 or high school and practice the three science domains of the California Science Test.
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Unofficial practice questions, not affiliated with the California Department of Education. Bank checked October 7, 2026.
The real test: California Science Test
Who takes it
Students in grade 5, in grade 8 and once in high school, in grade 10, 11 or 12. It is the science test of the CAASPP system.
What it covers
The California Next Generation Science Standards. Physical, Life, and Earth and Space Sciences each make one third; engineering items count in one of the three.
Standards by test
The grade 5 test draws on the standards of grades 3 to 5, the grade 8 test on grades 6 to 8 and the high school test on grades 9 to 12.
Format
Six segments on a computer: two of stand-alone questions (13 each in grade 5, 14 in grade 8, 16 in high school), one of either kind and three performance tasks.
Time
Untimed. The department expects about two hours.
Scores
Four achievement levels; no pass mark is published. Scale: 150 to 250 in grade 5, 350 to 450 in grade 8, 550 to 650 in high school. Level 3 from 214, 415, 615.
A class rolls the same toy car into a block of soft clay at three speeds. Slow: the dent is 2 millimeters deep. Medium: 5 millimeters. Fast: 9 millimeters. What do the results show?California Next Generation Science Standards, performance expectation 4-PS3-1, Energy (California Science Test blueprint domain: Physical Sciences)
A class tests three white powders. Powder X fizzes in vinegar and dissolves in water. Powder Y does not fizz and does not dissolve. Powder Z does not fizz but does dissolve. A mystery powder fizzes in vinegar and dissolves in water. Which powder is it most likely to be?California Next Generation Science Standards, performance expectation 5-PS1-3, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
A student in California and a student in Australia each let go of a ball. Which statement describes how both balls move?California Next Generation Science Standards, performance expectation 5-PS2-1, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
Show all 24 questions (21 more)
Physical Sciences, continued
A student pours one clear liquid into another. The mixture turns cloudy, and a white solid settles to the bottom. What is the best conclusion?California Next Generation Science Standards, performance expectation 5-PS1-4, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Ana turns on a lamp and can now see a book on her desk. Which model explains how she sees the book?California Next Generation Science Standards, performance expectation 4-PS4-2, Waves and Their Applications in Technologies for Information Transfer (California Science Test blueprint domain: Physical Sciences)
Leo puts a cup holding 200 grams of water on a scale. He stirs in 20 grams of sugar until he can no longer see it. What is the mass of the water and sugar together?California Next Generation Science Standards, performance expectation 5-PS1-2, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Maya seals the tip of a syringe that is full of air and pushes the plunger. It moves in a little, then springs back when she lets go. Which idea explains what she observes?California Next Generation Science Standards, performance expectation 5-PS1-1, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Two teams pull on a rope with equal strength in opposite directions. The rope does not move. Why?California Next Generation Science Standards, performance expectation 3-PS2-1, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
Life Sciences 8
A class draws the life cycles of a frog, a butterfly and a bean plant. The three drawings look very different. What do all three life cycles have in common?California Next Generation Science Standards, performance expectation 3-LS1-1, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
A flock of birds feeds in a field. A few birds at the edge watch for hawks and call out when one comes near. How does living in a group help these birds?California Next Generation Science Standards, performance expectation 3-LS2-1, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
A rabbit hears a twig snap and runs to its burrow. Which order of events explains this?California Next Generation Science Standards, performance expectation 4-LS1-2, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
A student grows a bean plant in a pot for a year and adds only water. The plant gains 500 grams. The dry soil loses 10 grams. Where did most of the plant's new material come from?California Next Generation Science Standards, performance expectation 5-LS1-1, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
In a forest, mushrooms grow on a fallen log. Over several years the log gets smaller and the soil under it gets richer. What role do the mushrooms play?California Next Generation Science Standards, performance expectation 5-LS2-1, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
Scientists find fossils of sea shells in rock high on a mountain. What do the fossils suggest?California Next Generation Science Standards, performance expectation 3-LS4-1, Biological Evolution: Unity and Diversity (California Science Test blueprint domain: Life Sciences)
Trees along a stream are cut down, and the water becomes warmer. What will most likely happen to the fish in the stream that need cold water?California Next Generation Science Standards, performance expectation 3-LS4-4, Biological Evolution: Unity and Diversity (California Science Test blueprint domain: Life Sciences)
Two puppies from the same litter grow up in different homes. One is given much more food and little exercise, and it becomes much heavier. What does this show?California Next Generation Science Standards, performance expectation 3-LS3-2, Heredity: Inheritance and Variation of Traits (California Science Test blueprint domain: Life Sciences)
Earth and Space Sciences 8
A class pours the same amount of water down two trays of soil set at the same slope. Tray 1 holds bare soil and loses 300 grams of soil. Tray 2 holds soil covered with grass and loses 40 grams. What do the results show?California Next Generation Science Standards, performance expectation 4-ESS2-1, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
A class records the rain in its town. January in four years: 14, 16, 12 and 15 centimeters. July in the same years: 1, 0, 2 and 1 centimeters. What is the best prediction for next year?California Next Generation Science Standards, performance expectation 3-ESS2-1, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
A cliff shows two rock layers. The lower layer holds fossils of land plants and no shells. The upper layer holds fossils of sea shells. What most likely happened here over time?California Next Generation Science Standards, performance expectation 4-ESS1-1, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
A town wants to make electricity from a resource that is renewable. Which resource fits?California Next Generation Science Standards, performance expectation 4-ESS3-1, Earth and Human Activity (California Science Test blueprint domain: Earth and Space Sciences); coal, natural gas and petroleum are fossil fuels: U.S. Energy Information Administration, Sources of energy
On a sunny day a class measures the shadow of a flagpole. At 9 a.m. it is 12 meters long. At noon it is 4 meters. At 3 p.m. it is 11 meters. What causes the shadow to change?California Next Generation Science Standards, performance expectation 5-ESS1-2, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
The roots of a tree grow into a crack in a rock and slowly split the rock. Which two of Earth's systems are interacting?California Next Generation Science Standards, performance expectation 5-ESS2-1, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
The sun looks far larger and brighter than the other stars. What is the reason?California Next Generation Science Standards, performance expectation 5-ESS1-1, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
Where is most of Earth's fresh water found?California Next Generation Science Standards, performance expectation 5-ESS2-2, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences); ocean water is saline: U.S. Geological Survey, Where is Earth's Water?
A metal spoon at 80 °C is placed in a cup of water at 20 °C. Which statement describes the transfer of energy?California Next Generation Science Standards, performance expectation MS-PS3-3, Energy (California Science Test blueprint domain: Physical Sciences)
A ringing bell hangs inside a sealed jar. As a pump removes the air, the sound fades away, although the bell can still be seen moving. What does this show?California Next Generation Science Standards, performance expectation MS-PS4-2, Waves and Their Applications in Technologies for Information Transfer (California Science Test blueprint domain: Physical Sciences)
A sealed syringe of air can be pushed from 60 milliliters down to 30 milliliters. A sealed syringe of water can hardly be pushed at all. Which model of matter explains the difference?California Next Generation Science Standards, performance expectation MS-PS1-4, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Show all 24 questions (21 more)
Physical Sciences, continued
A skater pushes on a wall with a force of 50 newtons. What force does the wall exert on the skater?California Next Generation Science Standards, performance expectation MS-PS2-1, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
A student pulls a 1-kilogram cart with a steady force, and its speed rises by 2 meters per second each second. She loads the cart to 2 kilograms and pulls with the same force. What happens?California Next Generation Science Standards, performance expectation MS-PS2-2, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
A table gives the kinetic energy of one cart at three speeds. At 1 meter per second: 2 joules. At 2 meters per second: 8 joules. At 3 meters per second: 18 joules. What does the pattern show?California Next Generation Science Standards, performance expectation MS-PS3-1, Energy (California Science Test blueprint domain: Physical Sciences)
In a sealed flask, 10 grams of one substance react completely with 5 grams of another. What is the total mass of the substances in the flask afterward?California Next Generation Science Standards, performance expectation MS-PS1-5, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Substance A melts at 30 °C and Substance B melts at 90 °C. After the two are mixed and heated, the product melts at 200 °C and differs from both in color and density. What does the evidence show?California Next Generation Science Standards, performance expectation MS-PS1-2, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
Life Sciences 8
A gardener plants a piece of stem cut from one plant. It grows roots and becomes a new plant, with no second parent. How does the new plant's genetic information compare with the parent plant's?California Next Generation Science Standards, performance expectation MS-LS3-2, Heredity: Inheritance and Variation of Traits (California Science Test blueprint domain: Life Sciences)
A rabbit eats grass. Later the rabbit dies, and decomposers break down its body. What happens to the atoms that made up the rabbit?California Next Generation Science Standards, performance expectation MS-LS2-3, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
A student looks at pond water under a microscope and sees a tiny organism made of one cell. It moves, takes in food and divides in two. What can the student conclude?California Next Generation Science Standards, performance expectation MS-LS1-1, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
A student places a water plant in a tube of water and counts the oxygen bubbles it gives off each minute. In bright light: 30 bubbles. In dim light: 8 bubbles. In darkness: 0 bubbles. What do the results support?California Next Generation Science Standards, performance expectation MS-LS1-6, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
A table follows a forest for four years. The acorn crop was large, small, large, small. The count of mice the next spring was 400, 120, 380, 110. What does the pattern suggest?California Next Generation Science Standards, performance expectation MS-LS2-1, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
On dark soil live 100 green beetles and 100 brown beetles, and birds hunt them by sight. A year later a count finds 20 green and 80 brown. Many generations later nearly all are brown. Which explanation fits?California Next Generation Science Standards, performance expectation MS-LS4-4, Biological Evolution: Unity and Diversity (California Science Test blueprint domain: Life Sciences)
Which part of a cell forms its boundary and controls what enters and leaves?California Next Generation Science Standards, performance expectation MS-LS1-2, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
Which statement about mutations, which are changes in genetic information, is accurate?California Next Generation Science Standards, performance expectation MS-LS3-1, Heredity: Inheritance and Variation of Traits (California Science Test blueprint domain: Life Sciences)
Earth and Space Sciences 8
A forecast gives a 70 percent chance of rain tomorrow. Why do forecasters give a chance and not a certain answer?California Next Generation Science Standards, performance expectation MS-ESS2-5, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
A geologist studies a stack of rock layers and the fossils in each one. What can the layers and fossils tell her by themselves?California Next Generation Science Standards, performance expectation MS-ESS1-4, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
According to California's science standards, which human activity is a major factor in the present rise of Earth's mean surface temperature?California Next Generation Science Standards, performance expectation MS-ESS3-5, Earth and Human Activity (California Science Test blueprint domain: Earth and Space Sciences)
Fossils of the same land animal are found in rocks of the same type on two continents that an ocean now separates. What does this evidence support?California Next Generation Science Standards, performance expectation MS-ESS2-3, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
What holds the planets, their moons and the asteroids in orbit around the sun?California Next Generation Science Standards, performance expectation MS-ESS1-2, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
Which two things drive the movement of water through the water cycle?California Next Generation Science Standards, performance expectation MS-ESS2-4, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
Why are minerals and fresh water plentiful in some places on Earth and scarce in others?California Next Generation Science Standards, performance expectation MS-ESS3-1, Earth and Human Activity (California Science Test blueprint domain: Earth and Space Sciences)
Why does a place in the Northern Hemisphere have summer when that hemisphere is tilted toward the sun?California Next Generation Science Standards, performance expectation MS-ESS1-1, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
A 2-kilogram cart moving at 3 meters per second hits a 1-kilogram cart at rest. The carts stick together, and friction is small enough to ignore. How fast do they move just after the collision?California Next Generation Science Standards, performance expectation HS-PS2-2, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
A cart at rest at the top of a track has 500 joules of gravitational potential energy. At the bottom it has 440 joules of kinetic energy and no potential energy. What happened to the other 60 joules?California Next Generation Science Standards, performance expectation HS-PS3-1, Energy (California Science Test blueprint domain: Physical Sciences)
A student pulls a cart with three net forces and measures its acceleration. With 2 newtons: 1 m/s². With 4 newtons: 2 m/s². With 6 newtons: 3 m/s². What is the mass of the cart?California Next Generation Science Standards, performance expectation HS-PS2-1, Motion and Stability: Forces and Interactions (California Science Test blueprint domain: Physical Sciences)
Show all 24 questions (21 more)
Physical Sciences, continued
A student times the same reaction at three temperatures. At 10 °C it takes 120 seconds. At 25 °C it takes 60 seconds. At 40 °C it takes 30 seconds. Which explanation fits the data?California Next Generation Science Standards, performance expectation HS-PS1-5, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
A wave on a rope has a frequency of 4 hertz and a wavelength of 0.5 meter. How fast does the wave travel?California Next Generation Science Standards, performance expectation HS-PS4-1, Waves and Their Applications in Technologies for Information Transfer (California Science Test blueprint domain: Physical Sciences)
Elements in the same column of the periodic table have similar chemical properties. What explains this pattern?California Next Generation Science Standards, performance expectation HS-PS1-1, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
In a closed container, 4 grams of hydrogen react completely with 32 grams of oxygen, and water is the only product. What mass of water forms?California Next Generation Science Standards, performance expectation HS-PS1-7, Matter and Its Interactions (California Science Test blueprint domain: Physical Sciences)
In an insulated cup, 100 grams of water at 80 °C are mixed with 100 grams of water at 20 °C. What is the temperature once the mixture settles?California Next Generation Science Standards, performance expectation HS-PS3-4, Energy (California Science Test blueprint domain: Physical Sciences)
Life Sciences 8
A field is sprayed with the same insecticide each year. In year 1 the spray kills 98 percent of a pest insect. In year 5 it kills 40 percent. Which explanation fits?California Next Generation Science Standards, performance expectation HS-LS4-4, Biological Evolution: Unity and Diversity (California Science Test blueprint domain: Life Sciences)
A student records her heart rate: 70 beats per minute at rest, 130 during a run and 75 five minutes after she stops. What does the return toward 70 show?California Next Generation Science Standards, performance expectation HS-LS1-3, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
Genes are regions of a cell's DNA. What do genes contain?California Next Generation Science Standards, performance expectation HS-LS1-1, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
In cellular respiration, bonds in food molecules and oxygen molecules break and new compounds form. What does this process provide for an animal?California Next Generation Science Standards, performance expectation HS-LS1-7, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
In most ecosystems there are far fewer top predators than plant eaters. What explains this?California Next Generation Science Standards, performance expectation HS-LS2-4, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
Six counts of the deer on an island, taken a few years apart, give 50, 120, 260, 400, 410 and 405. What best explains why the population levels off near 400?California Next Generation Science Standards, performance expectation HS-LS2-1, Ecosystems: Interactions, Energy, and Dynamics (California Science Test blueprint domain: Life Sciences)
Which of these is a source of new genetic variation in a population?California Next Generation Science Standards, performance expectation HS-LS3-2, Heredity: Inheritance and Variation of Traits (California Science Test blueprint domain: Life Sciences)
Which statement describes what photosynthesis does?California Next Generation Science Standards, performance expectation HS-LS1-5, From Molecules to Organisms: Structures and Processes (California Science Test blueprint domain: Life Sciences)
Earth and Space Sciences 8
A city compares three ways to produce energy. A table lists costs and benefits for each one. What should the city expect of whichever option it chooses?California Next Generation Science Standards, performance expectation HS-ESS3-2, Earth and Human Activity (California Science Test blueprint domain: Earth and Space Sciences)
A lamp shines for ten minutes on equal masses of dry sand and water. The sand warms by 12 °C and the water by 3 °C. Which property of water does this show?California Next Generation Science Standards, performance expectation HS-ESS2-5, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
According to Kepler's laws, what is the shape of a planet's path around the sun?California Next Generation Science Standards, performance expectation HS-ESS1-4, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
How did plants and other organisms change Earth's atmosphere over time?California Next Generation Science Standards, performance expectation HS-ESS2-7, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
Light from distant galaxies is shifted toward the red end of the spectrum. What does this observation support?California Next Generation Science Standards, performance expectation HS-ESS1-2, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
Scientists date the rock of the ocean floor at three distances from a mid-ocean ridge. The rock at the ridge is youngest. It is older 100 kilometers away and older still 200 kilometers away. What does the pattern support?California Next Generation Science Standards, performance expectation HS-ESS1-5, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
Warming melts glacial ice. With less ice, Earth's surface reflects less sunlight, which raises surface temperatures and melts more ice. What kind of process is this?California Next Generation Science Standards, performance expectation HS-ESS2-2, Earth's Systems (California Science Test blueprint domain: Earth and Space Sciences)
Which process in the core of the sun releases the energy that reaches Earth as radiation?California Next Generation Science Standards, performance expectation HS-ESS1-1, Earth's Place in the Universe (California Science Test blueprint domain: Earth and Space Sciences)
Unofficial practice with our own questions for the California Science Test (CAST), the CAASPP science test given in grades 5 and 8 and once in high school. Not affiliated with, endorsed by or sponsored by the California Department of Education.
Read the full guide
What the CAST covers
Physical Sciences, Life Sciences and Earth and Space Sciences each make one third of the test. The grade 5 test draws on the state science standards of grades 3 to 5, the grade 8 test on grades 6 to 8 and the high school test on grades 9 to 12.
How these questions are built
Each set has 24 questions, eight for each domain. Most begin with a short investigation or a few made-up measurements, because the real test asks students to reason from evidence. Every answer was checked against the text of the standard named under it.
Read each investigation twice before you choose: what changed, and what was measured?
Questions and answers
What is on the CAASPP science test?
The CAASPP science test is the California Science Test, or CAST. It tests the California Next Generation Science Standards in three domains, physical, life, and earth and space sciences, with stand-alone questions and performance tasks.
What grades take the CAST?
Grade 5, grade 8 and once in high school, in grade 10, 11 or 12. A high school may test in grade 10 or 11, and a grade 12 student who has not yet tested is registered automatically.
How long is the CAST science test?
It is untimed. The California Department of Education expects about two hours for its six segments: stand-alone questions first, then performance tasks of four to six questions each.
How is the CAST scored?
By scale score in four achievement levels, with no pass mark. Scores run from 150 to 250 in grade 5, 350 to 450 in grade 8 and 550 to 650 in high school; Level 3 begins at 214, 415 and 615.
Where is the official California Science Test practice test?
The state's own CAST practice and training tests are on the CAASPP and ELPAC website, caaspp-elpac.org, under Practice and Training Tests.