Washington Comprehensive Assessment of Science (WCAS) Grade 5 common mistakes
Washington Comprehensive Assessment of Science (WCAS) Grade 5 · Understand the traps and how to avoid them.
When asked whether a material is a solid or liquid, the student answers from the object's name (e.g., 'sand is a liquid because it pours') instead of describing the observed properties of the sample in front of them.
Everyday language and product names ('sand timer', 'liquid soap') supply a label, so the student skips the step of gathering evidence and just retrieves a word.
What to do instead
Have students write two columns, 'what I observe' and 'what I conclude', and require at least two observations (holds its own shape? takes the shape of the container? flows?) before any label is written.
When explaining why a puddle dries up, the student says the water 'disappears' or 'is gone' rather than describing water moving into the air as a gas.
The change is invisible, so a young learner's default explanation for an invisible change is disappearance rather than a change of state.
What to do instead
Practice with a physical model: seal a wet paper towel in a clear bag and have students draw arrows showing where the water went, then use the word 'evaporated' in a complete sentence with the direction of movement.
Given a table of sunrise times across a month, the student reads off one row and answers about the trend, or mixes metric units when comparing distances and masses.
Students attend to the single number they can find rather than comparing rows, and they have not internalized which unit goes with which kind of measurement.
What to do instead
Teach a two-step routine: circle the column being compared, then state 'as ___ increases, ___ decreases'. Pair this with a unit-sort activity (grams, meters, liters, degrees Celsius) before any data question.
When asked to predict what happens when a moving object is pushed, the student uses the word 'force' as if it were a substance the object carries, saying 'it ran out of force' instead of describing the push and the resulting change in motion.
Force is invisible and abstract, so students substitute a familiar object-like story for the cause-and-effect relationship between a push or pull and a change in speed or direction.
What to do instead
Use a consistent sentence frame: 'A ___ pushed/pulled on the ___, so its motion ___.' Have students act out and label pushes and pulls with arrows on a drawing before writing the explanation.
When asked what a plant needs to grow, the student lists 'soil' as a food source, or says plants get their food from the soil rather than making it using light.
The plant-food idea is repeated in everyday talk and in gardening contexts, and the invisible process of making food from light is harder to picture than something taken up from dirt.
What to do instead
Grow the same seeds in soil, in wet paper, and in water only, and have students record growth. Then state explicitly: plants make their own food using light; soil supplies water and minerals.
When explaining why a deer population drops after a hard winter, the student names a single cause and stops, or says the animals 'decided' to die or move.
Young learners prefer one-cause stories and often attribute population changes to intention rather than to food, water, shelter, and space limits acting together.
What to do instead
Have students build a simple food-and-shelter web for one habitat and mark with arrows which resources the hard winter reduced, then write an explanation naming at least two limiting factors.
When asked to compare the life cycles of a frog and a beetle, the student describes only the frog and assumes the other animal's stages are the same, or claims the animal 'turns into a different animal' during metamorphosis.
The frog life cycle is heavily practiced in early grades, so students over-generalize it and lack a second, contrasting example to reason from.
What to do instead
Compare two life cycles side by side using a chart with the same headings (egg, young, adult), and have students mark which stages look like the adult and which do not, then state one similarity and one difference in writing.
When asked how a given trait is inherited, the student says the offspring 'chooses' its traits or that it looks like the parent because it wants to.
Inheritance is invisible and intention-based reasoning is a comfortable default for explaining resemblance.
What to do instead
Use data, not stories: give a table of parents and offspring traits for several litters or seedlings and have students find the pattern, then write 'the offspring inherited ___ from the parent' using the table as evidence.
When asked what happens to rainwater that falls on a hill, the student says the water 'goes into the ground' and stops, without connecting it to runoff into streams, or describes the water cycle as a one-way path from clouds to ground.
The water cycle diagram is often memorized as a circle of labels rather than as a set of connected pathways, and groundwater is invisible.
What to do instead
Use a stream table or a tilted tray of soil with a spray bottle and have students trace with their finger where the water actually travels, then label the same route on a diagram with arrows pointing in more than one direction.
When asked how wind or water changes a landscape, the student says the change happens 'all at once' or confuses a fast event (flood, landslide) with slow erosion over many years.
Human time sense is short, so processes that take thousands of years get collapsed into a single dramatic event, and the two are rarely contrasted in instruction.
What to do instead
Have students sort picture cards of changes into 'fast' and 'slow' and justify each with a time estimate, then write one sentence explaining how many small slow changes could add up to a large one.