Kagawa Entrance Science common mistakes
Kagawa Entrance Science · Understand the traps and how to avoid them.
In Mathematics I/II integration problems, students compute an indefinite integral and then substitute the limits without checking whether the integrand changes sign or whether the region must be split (e.g., integrating |x-1| or an area between two curves that cross inside the interval).
Drilling tends to focus on antiderivative mechanics, so the candidate treats every definite integral as a single plug-in step and skips the sketch that would reveal a crossing point or absolute value.
What to do instead
Before evaluating any definite integral, sketch the curves or sign chart of the integrand on the interval, mark all zeros and intersection points, and split the integral at each. Write the area as a sum of integrals of |f-g| decomposed by sign, then evaluate. Practice with three crossing-point problems per session until splitting is automatic.
In Mathematics A (counting, probability, sequences), students answer 'at least one' questions by adding single-case probabilities (P(exactly one)+P(exactly two)+...) but omit or double-count cases, or they forget that drawing without replacement changes the denominator on each draw.
Combinatorial problems reward fast pattern-matching, and candidates memorize a formula shape without tracking the sample space, so the complement and the with/without-replacement distinction get lost under time pressure.
What to do instead
For every probability item, first write the sample space explicitly (ordered/unordered, replacement or not) and label it. Prefer the complement P(at least one)=1-P(none) and verify by computing both routes. For sequences, list the first four terms and confirm the recurrence before summing.
In Physics mechanics, students substitute numbers into F=ma or energy equations without drawing a free-body diagram, so they miss a normal force, tension, or friction component and get a plausible but wrong magnitude; they also mix up which quantity is conserved when friction acts.
Formula recall is easier than spatial reasoning, and under exam time limits the diagram feels like overhead, so the candidate jumps to algebra and silently drops forces acting at angles.
What to do instead
Make a labeled free-body diagram mandatory for every mechanics problem, with axes chosen along the acceleration. State in writing which forces do work and whether mechanical energy is conserved; if friction acts, use the work-energy theorem with W_friction. Then write component equations before touching numbers.
In Physics electricity and waves, students apply Ohm's law or the lens/mirror equation with the wrong sign convention or to the wrong element-treating a series-parallel network as uniform, or placing a virtual image on the same side as a real one.
Sign conventions and network reduction are taught as rules to memorize rather than as consequences of definitions, so they collapse when a circuit has both series and parallel branches or a diverging lens.
What to do instead
Redraw compound circuits step by step, labeling each equivalent resistance and the current through each branch. For optics, write the sign convention (real/virtual, converging/diverging) at the top of the page before substituting, and check the sign of the image distance against a ray sketch.
In Chemistry stoichiometry and gas problems, students balance the equation but then use the coefficient ratio in the wrong direction, or apply the ideal gas law with volume in mL or temperature in °C without converting to L and K.
The arithmetic is routine, so attention goes to balancing and the unit conversions are treated as an afterthought; mol ratios are also applied by feel rather than by dimensional analysis.
What to do instead
Carry units through every calculation and cancel them explicitly (mol → mol → g or L). Write the mol ratio as a fraction with the known substance in the denominator and check it by dimensional analysis. Convert to kelvin and liters as the first line of any gas problem, before reading the rest.
In Chemistry acid-base and equilibrium items, students compute pH from concentration without checking whether the acid is weak (ignoring the dissociation degree) or assume a buffer's pH equals that of its components, and they confuse oxidation and reduction half-reactions in electrochemistry.
Strong-acid shortcuts are overlearned, and equilibrium reasoning requires tracking two coupled variables (concentration and Ka/Kb) that the candidate tries to collapse into one formula.
What to do instead
Classify the species first (strong/weak acid or base, buffer, salt) and only then choose the method: for weak acids set up the Ka expression with x and check x<<C0 before approximating. For redox, assign oxidation numbers to every atom and write separate half-reactions, balancing charge explicitly.
In Biology, students answer genetics and cell-division questions by recalling a diagram rather than tracing the actual cross or stage, so they misassign genotypes in a dihybrid cross or confuse the chromosome number and chromatid count at meiosis I versus II.
Biology content is voluminous and often studied by image recognition, so candidates reproduce a remembered figure instead of applying the segregation and independent-assortment logic to the specific parents given.
What to do instead
For genetics, always write the parental genotypes, the gametes each can produce, and a Punnett square or branch diagram before stating a ratio. For meiosis, make a table of stage versus chromosome number, chromatid number, and DNA content, and fill it from first principles for each question.
In Earth Science/Geology, students read a cross-section or stratigraphic column by assuming the top layer is always youngest and the bottom oldest, ignoring folding, faulting, or intrusion that reorders the sequence, or they misread a contour map's slope direction.
The principle of superposition is taught first and becomes a default, while deformation and intrusive contacts are treated as exceptions to memorize rather than as evidence to interpret.
What to do instead
For any cross-section, apply the principles in order: superposition, original horizontality, cross-cutting relationships, and inclusions. Identify faults and intrusions and state which units they cut. On contour maps, draw the flow direction perpendicular to contours and label uphill/downhill before answering.
In English reading and composition, students answer detail questions from a single keyword match in the passage without locating the sentence that actually supports the claim, and in writing they produce grammatically correct sentences that never state a thesis or link evidence to it.
Keyword scanning is faster than full comprehension, and composition practice often rewards sentence-level accuracy over argument structure, so the candidate never learns to build a claim-evidence-link paragraph.
What to do instead
For reading, underline the exact sentence supporting each answer and reject options that are true in general but not stated in the passage. For writing, draft a one-sentence thesis and an outline of claim → evidence → interpretation before writing, then check every paragraph ends by connecting back to the thesis.
In Japanese Language and in data-interpretation items across the sciences, students answer from the passage's overall impression or from a single striking data point rather than from the logical structure-missing the contrast particle that reverses the argument or ignoring error bars and sample size in a graph.
Both domains require holding structure in working memory while reading, and candidates default to gist or to the most visually salient number, especially when a graph's axis scale or a passage's concessive construction is easy to skim past.
What to do instead
For Japanese passages, mark the topic sentence and every contrast or causal connective (however, therefore, in fact) and summarize the argument in one line before answering. For data items, state the axes, units, sample size, and uncertainty first, then describe the trend in words and only then evaluate the options.