CAST Science Test: What Grades 5 and 8 Cover and How to Prepare
If you have a child in a California public school, the CAST Science test is the one science exam the state asks them to take — and the results are sobering. On the 2024-25 CAST, only about a third of California students met or exceeded the science standard, which means roughly two in three did not, according to the California Department of Education. Understanding what the CAST Science test actually measures makes it far easier to help your child get ready the right way.
What is the CAST?
CAST stands for the California Science Test, part of the state's CAASPP testing system. Students take it three times in their school career: once in grade 5, once in grade 8, and once in high school (grade 10, 11, or 12). It measures the California Next Generation Science Standards (CA NGSS). It is a grade-span assessment, so the grade 5 test covers the science of grades 3 through 5 (building on K-2 foundations) and the grade 8 test spans grades 6 through 8.
What the CAST covers
NGSS science is three-dimensional: students are expected to know the core ideas, use science and engineering practices, and connect crosscutting concepts across three domains — Physical Sciences, Life Sciences, and Earth and Space Sciences. The CAST reflects that. It combines discrete, stand-alone questions with performance tasks that ask students to analyze a scenario, interpret data, and explain their reasoning. It is not a recall quiz; it rewards students who can actually apply what they know.
Why the CAST is hard for so many students
Two things combine. First, NGSS asks for application and explanation, not just facts — a higher bar than many families expect. Second, in a lot of elementary classrooms science is squeezed in around reading and math rather than taught daily, so the three-year foundation each CAST assesses was never fully built. The result shows in the numbers: on the 2024-25 CAST, about 21% of students met the standard and 11% exceeded it, while the remaining two-thirds landed in Standard Nearly Met or Standard Not Met, per California Department of Education results.
How to prepare for the CAST Science test
Because the CAST is cumulative and application-heavy, the students who do well are the ones who built understanding steadily over years. Three habits help most: cover all three domains — physical, life, and earth and space — rather than a child's favorite; practice explaining and applying concepts, not just naming them; and make sure every missed question gets explained so it turns into a corrected idea.
That is exactly how eiveon's science course works. It runs grade by grade for grades 1 through 8, and every chapter is mapped to the NGSS (alongside Texas TEKS and ten more US state frameworks), shown chapter by chapter on the curriculum page. For grades 5 and 8 — the elementary and middle-school CAST administrations — every chapter is tagged to the NGSS and covers the physical, life, and earth and space science the test draws on. Each topic runs Learn, then Practice with every answer explained, then Apply with exam-style questions. The goal is to build the NGSS knowledge the CAST assesses in grades 5 and 8, a little every day — not to drill one test or promise a particular score. (The high-school CAST sits beyond eiveon's grades 1-8 range.)
What grades take the CAST?
Students take the CAST once in grade 5, once in grade 8, and once in high school. The grade 5 result is an early signal of whether the elementary science foundation is in place, and grade 8 checks the middle-school years before high-school science begins.
What is a passing score on the CAST?
The CAST reports four achievement levels: Standard Not Met, Standard Nearly Met, Standard Met, and Standard Exceeded. Scoring at Standard Met or Standard Exceeded is what it means to meet the state science standard. As the recent results show, that is where only about a third of students currently land — which is why starting early, and staying consistent, matters so much.