Ehime Entrance Science common mistakes
Ehime Entrance Science · Understand the traps and how to avoid them.
Calculating a numerical answer (speed, density, concentration) and writing only the number, omitting the unit or writing it in the wrong unit (e.g., g/cm³ instead of kg/m³) after having converted mid-calculation.
Candidates focus on getting the arithmetic right and treat units as decoration; when they convert grams to kilograms partway through, they forget to carry the conversion into the final unit label, or they copy the unit from the question without adjusting for the conversion they performed.
What to do instead
Before substituting numbers, write the target unit at the end of the working line and track each conversion explicitly (e.g., 250 g = 0.25 kg written above the substitution). After computing, do a unit-cancellation check: multiply out the units of the quantities used and confirm they reduce to the target unit. If they do not, the conversion step is missing.
Describing a phenomenon by naming it ("because of inertia", "because of osmosis", "because of convection") rather than stating the mechanism or the direction of change that the question asks for.
Textbook headings and term names are the most memorable part of study, so candidates retrieve the label first and assume it constitutes an explanation; they do not check whether the question asks for a cause, a direction, or a magnitude.
What to do instead
Adopt a two-part answer template: name the principle, then state what it implies for this specific situation (which object moves which way, which quantity increases, which side gains water). Practise rewriting every one-line answer into a "principle + consequence for this case" sentence until it becomes automatic.
Reading a graph or table and reporting the value at the wrong point: reading the y-value at x = 0 instead of the gradient, or averaging two data points instead of reading the trend, then stating a conclusion the data do not support.
Under time pressure candidates grab the first number they see on the axis; they also conflate "value of the quantity" with "rate of change of the quantity" because both are plotted on the same figure.
What to do instead
Before answering, write down what each axis represents and its unit, then write which of the three the question wants: a value, a gradient, or an area. For gradient questions, mark two well-separated points on the line and show the subtraction explicitly. Reject any conclusion that requires data outside the plotted range.
In chemistry, writing a balanced equation that conserves atoms but omits state symbols or charges, or balancing only the atoms the candidate happens to check (often H and O) while leaving another element unbalanced.
Candidates balance by inspection and stop as soon as the equation "looks right"; they rarely do a systematic element-by-element count, and state symbols are treated as optional annotation rather than part of the answer, especially in ionic equations where charge balance is a separate requirement.
What to do instead
Use a fixed checklist after every equation: count each element on both sides in a table, then check total charge on both sides for ionic equations, then add state symbols. For ionic equations, cancel spectator ions last and re-verify charge balance after cancelling.
Confusing genotype and phenotype notation or describing inheritance in terms of the visible trait when the question asks for the genetic constitution (or vice versa), and failing to distinguish homozygous from heterozygous in the reasoning.
The two concepts are taught together and share vocabulary; candidates also memorise example ratios (3:1, 1:1) without the condition that produces them, so they apply a ratio to a cross where it does not hold.
What to do instead
Write the parental genotypes with defined symbols before drawing any cross, and label the resulting boxes as genotype; derive phenotype only in a separate step. State the condition for any ratio you quote (e.g., a 3:1 ratio requires heterozygote × heterozygote with complete dominance).
Treating a scalar and a vector as interchangeable: giving a speed when velocity is asked, omitting direction for a force or displacement, or adding magnitudes of perpendicular vectors arithmetically.
Everyday language uses "speed" and "velocity" interchangeably, and candidates default to the familiar magnitude; vector addition by simple arithmetic feels natural because the numbers are small.
What to do instead
Whenever a quantity has a direction, write the direction in the answer even if the question does not explicitly demand it. For perpendicular vectors, always draw the triangle and use Pythagoras for magnitude and trigonometry for angle; never add magnitudes directly unless the vectors are collinear and same-signed.
Answering an Earth Science question about geological time, rock formation order, or fossil succession by intuition about which rock "looks older" rather than applying superposition, cross-cutting relationships, or index fossils.
Field and diagram questions present a static picture with no explicit ordering cue, and candidates lack a habitual procedure for extracting relative age, so they guess from position or appearance.
What to do instead
Apply a fixed sequence to every geological diagram: identify undisturbed layers, apply superposition (lower is older), then identify cross-cutting features (faults, intrusions) as younger than what they cut, then look for index fossils to correlate. Write the ordering as a numbered list before answering.
In physics calculations, substituting values into a formula without first converting all quantities to consistent SI units, producing an answer off by factors of 1000 or 3600.
Questions often supply data in convenient units (cm, g, minutes, km/h) and candidates substitute directly because the formula is recalled in symbols with no units attached.
What to do instead
Keep a conversion line at the top of the working area and convert every given value to SI before substitution, writing the converted value next to the original. Check the order of magnitude of the result against the physical situation (a falling object's speed should be a few m/s, not thousands).
Describing an experimental procedure or observation without a control or without stating what is varied, held constant, and measured, so the conclusion cannot be attributed to the manipulated variable.
Candidates describe what they did rather than the logic of the design; the vocabulary of independent, dependent, and controlled variables is known but not applied when writing free responses.
What to do instead
Before writing, fill three slots explicitly: what I change, what I measure, what I keep the same. State the control condition and why it is needed. Then phrase the conclusion as "because only X differed, the change in Y is attributed to X".
Leaving a multi-part question partially answered because the candidate spends the remaining time perfecting one long free-response answer and never returns to the short items.
Marks are perceived as proportional to effort, so candidates over-invest in the answer they find easiest or most interesting; there is no time budget, and the paper is reviewed only if time remains, which it usually does not.
What to do instead
At the start, count the items and allocate minutes per item; answer every item at least minimally before deepening any single one. Mark uncertain items and return to them. A one-line correct answer to a short item scores the same as a polished paragraph and costs far less time.