100+ Free CAST High School Practice Questions
Prepare for the California Science Test (CAST) — High School exam with instant access — no signup required.
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Key Facts: CAST High School Exam
Once in HS
Taken once in grade 10, 11, or 12 (LEA rules)
cde.ca.gov CAASPP science
~2 hours
Untimed; estimated about two hours for three segments
caaspp-elpac.org CAST
32–34 + PTs
Segment A discrete items plus 2 performance tasks for student scores
Revised CAST Blueprint
3 domains
Physical, Life, Earth & Space Sciences with integrated ETS
CAST Blueprint
CA NGSS 9–12
Aligned to high school California Next Generation Science Standards
CDE CAST page
Free
State-funded CAASPP assessment; no family exam fee
Statewide assessment program
4 levels
Minimal, Developing, Proficient, Advanced; High school Proficient is 615–635
CDE CAST Range ALDs (2025–26 labels)
71 PEs
Item specifications cover 71 Performance Expectations for high school form
CDE CAST Item Specifications
CAST High School is California’s free once-in-high-school CA NGSS science test (CDE/CAASPP), untimed (~2 hours), three science domains plus integrated engineering, four achievement levels.
Sample CAST High School Practice Questions
Try these sample questions to test your CAST High School exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1An atom of chlorine-37 has an atomic number of 17. How many neutrons are in its nucleus?
2Which change would convert a nitrogen atom into a different element?
3Moving left to right across a period on the periodic table, atomic radius generally decreases. What best explains this trend?
4In the balanced equation 2 H₂ + O₂ → 2 H₂O, how many moles of water form when 3.0 mol of H₂ react completely with excess oxygen?
5A student burns methane and measures a temperature increase in the surroundings. How should the reaction energy change be classified for the chemical system?
6Which statement correctly describes nuclear fission as used in many power reactors?
7A 1,200 kg car traveling at 20 m/s is brought to rest by braking over 4.0 s. What is the magnitude of the average net force on the car? (Use F = Δp/Δt.)
8Two ice skaters push off from each other on frictionless ice. Skater A has twice the mass of skater B. Immediately after they push, which statement is true?
9A 4.0 kg object is lifted 2.0 m vertically at constant speed. How much gravitational potential energy does it gain? (Use g = 10 m/s² and PE = mgh.)
10A 0.50 kg ball rolls at 4.0 m/s. What is its kinetic energy? (Use KE = ½mv².)
About the CAST High School Exam
The California Science Test (CAST) High School is California’s statewide CAASPP science assessment taken once in high school (grade 10, 11, or 12). It measures the California Next Generation Science Standards (CA NGSS) for grades 9–12 across Physical Sciences, Life Sciences, and Earth and Space Sciences, with Engineering, Technology, and Applications of Science integrated by context. The computer-based form uses discrete items and performance tasks and is untimed (about two hours estimated). OpenExamPrep free MCQ practice is an English-language study aid aligned to CAST domains and CA NGSS—not official secure content or a full simulation of multi-part performance tasks.
Assessment
Question count not published by the exam provider
Time Limit
Untimed; estimated about two hours for all three segments (CDE/CAASPP).
Passing Score
No pass/fail score. Four overall achievement levels: Level 1 Minimal, Level 2 Developing, Level 3 Proficient, Level 4 Advanced (labels adopted by the SBE and used from 2025–26 reporting; formerly Standard Not Met / Nearly Met / Met / Exceeded). Cut scores unchanged: High school scale 550–650, Proficient 615–635, Advanced 636–650. Domain results use Above Proficient / At or Near Proficient / Below Proficient.
Exam Fee
Free to students and families; CAST is state-funded and administered through California public schools as part of CAASPP. (California Department of Education (CAASPP); operational delivery via the CAASPP contractor (ETS))
CAST High School Exam Content Outline
Physical Sciences (with integrated ETS)
Matter and chemical reactions, forces and interactions, energy, and waves at high school depth; Engineering, Technology, and Applications of Science items assigned by stimulus context.
Life Sciences (with integrated ETS)
Molecular to organism structure and processes, ecosystems, heredity, and biological evolution with SEPs and CCCs at grades 9–12 depth.
Earth and Space Sciences (with integrated ETS)
Earth’s place in the universe, Earth’s systems, and Earth and human activity (including climate and resource use), with Environmental Principles and Concepts context where appropriate.
How to Pass the CAST High School Exam
What You Need to Know
- Passing score: No pass/fail score. Four overall achievement levels: Level 1 Minimal, Level 2 Developing, Level 3 Proficient, Level 4 Advanced (labels adopted by the SBE and used from 2025–26 reporting; formerly Standard Not Met / Nearly Met / Met / Exceeded). Cut scores unchanged: High school scale 550–650, Proficient 615–635, Advanced 636–650. Domain results use Above Proficient / At or Near Proficient / Below Proficient.
- Assessment: Question count not published by the exam provider
- Time limit: Untimed; estimated about two hours for all three segments (CDE/CAASPP).
- Exam fee: Free to students and families; CAST is state-funded and administered through California public schools as part of CAASPP.
Keys to Passing
- Complete 500+ practice questions
- Score 80%+ consistently before scheduling
- Focus on highest-weighted sections
- Use our AI tutor for tough concepts
CAST High School Study Tips from Top Performers
Frequently Asked Questions
What is CAST High School?
CAST is California’s statewide science assessment in the CAASPP System. High school students take CAST once (grade 10, 11, or 12 depending on LEA decisions) assessing CA NGSS Performance Expectations from grades 9–12.
Who takes high school CAST?
Students take CAST once in high school. LEAs may administer it in grade 10 or 11; grade 12 students who have not yet tested are automatically registered. Students repeating grade 12 are not eligible. Students with IEPs designating alternate assessment take the CAA for Science instead.
How long is CAST?
CAST is untimed. CDE/CAASPP estimate about two hours for all three segments.
What domains are scored?
Students receive an overall score and domain scores for Physical Sciences, Life Sciences, and Earth and Space Sciences. Engineering items are assigned to a science domain based on stimulus context (CAST blueprint).
Is CAST free?
Yes. CAST is state-funded and administered through public schools at no cost to families for standard administration.
What language is the CAST given in?
The CAST is delivered in English. Eligible students may receive the Spanish stacked–dual language designated support, which displays a full Spanish translation of each item above the English version, and CDE publishes non-embedded translated CAST test directions in sixteen additional languages. OpenExamPrep practice questions are English-language only.
Are these practice questions official CAST items?
No. OpenExamPrep questions are English-language MCQ study adaptations aligned to CA NGSS and CAST domains. They do not reproduce secure items or fully simulate multi-part performance tasks and technology-enhanced item types.