TACHS common mistakes
TACHS · Understand the traps and how to avoid them.
Spending a fixed amount of time on every reading passage instead of letting passage difficulty set the pace, so an easy passage gets over-analyzed while a dense one is rushed at the end.
Candidates practice passages one at a time and never rehearse the full timed set, so they lack a sense of how long the whole section should take and default to equal time per passage.
What to do instead
Do full-length timed reading sets and log the minutes per passage. Target roughly 8–9 minutes for a passage with 6–8 questions, bank the leftover seconds from easy passages, and deliberately move faster on the last passage so you never leave questions blank.
Answering detail questions from memory of the passage instead of returning to the lines, then picking an option that sounds familiar but is subtly wrong.
The passages are short enough to feel memorizable, and answer choices are written to echo the passage's wording, so recollection feels reliable when it is not.
What to do instead
For every detail or vocabulary-in-context question, physically point to the line(s) and verify each option against that text. Eliminate any choice whose support you cannot locate. Practice by marking the line number next to each answer before selecting it.
Choosing an answer that is true in real life or true somewhere in the passage but does not answer the specific question asked, especially on main-idea and inference items.
Under time pressure the brain latches onto any statement it recognizes as correct, and main-idea options are often deliberately broad or narrow versions of the passage's actual point.
What to do instead
Restate the question in your own words before reading the options, then test each choice against that restatement. For main idea, check that the choice covers the whole passage, not one paragraph; for inference, confirm the conclusion is forced by the text rather than merely plausible.
Treating grammar and usage items as 'which sounds right' rather than applying a rule, so errors like subject-verb agreement across an interrupting phrase or a misplaced modifier slip through.
Everyday speech tolerates these constructions, so the ear accepts them; candidates have not drilled the specific error types the section recycles.
What to do instead
Learn a short checklist (subject-verb agreement, pronoun reference, misplaced/dangling modifier, parallel structure, tense consistency, run-on/comma splice) and run each sentence through it. Practice by finding the error before looking at the choices, then match your finding to an option.
Revising a sentence by picking the option that changes the most or sounds most sophisticated, rather than the one that fixes the error with the fewest changes.
Candidates equate 'better writing' with fancier vocabulary or longer sentences, and test writers exploit this by offering wordy, over-edited distractors.
What to do instead
Prefer the shortest option that is grammatically correct and preserves the original meaning; eliminate any choice that adds information, drops a needed qualifier, or shifts tense. When two options are both correct, choose the more concise and direct one.
Solving multi-step word problems by grabbing the first numbers seen and applying an operation, skipping the step of identifying what the question actually asks for.
Word problems embed extra numbers and require a plan; under timed conditions candidates pattern-match to a familiar operation instead of translating the situation.
What to do instead
Before computing, write one line stating what is being asked (e.g., 'find cost per person, not total cost'), list the given quantities, and note the unit of the answer. Estimate the answer first, then compute, then check the result against the estimate and the units.
Losing points on fractions, decimals, percents, and ratios because of conversion and simplification slips rather than conceptual gaps.
These topics are taught in isolation, so candidates do not automatically convert between forms or simplify before multiplying, and small arithmetic errors compound.
What to do instead
Drill a fixed routine: convert everything to one form before operating, simplify fractions before multiplying, and convert a final answer back to the requested form. Do 10 mixed-format items daily and check by estimating (e.g., 3/7 is a bit under 0.5).
Misreading geometry and measurement items by using the wrong formula or forgetting units, such as confusing perimeter with area or mixing up radius and diameter.
Formulas are memorized as strings without the associated diagram meaning, and word problems often give the diameter while the formula needs the radius.
What to do instead
Keep a one-page formula sheet and annotate each formula with what it measures. On every problem, sketch or label the figure, circle the given dimension, convert it to the form the formula needs, and write units on the answer.
On reasoning items, abandoning a pattern or analogy after a few seconds and guessing, or assuming the sequence must involve a constant difference.
Reasoning questions are designed to look simple but use alternating operations, two interleaved sequences, or relationships based on function rather than category; candidates stop at the first failed hypothesis.
What to do instead
Use a systematic search: for number series, check differences, then ratios, then alternating terms, then squares/cubes; for analogies, state the relationship in a sentence and test it against every option. Give each item a fixed budget (about 45–60 seconds) before marking and returning.
Leaving answers blank or mismarking the answer sheet because of pacing and bubbling errors near the end of a section.
There is no penalty for wrong answers on this exam, but candidates run out of time and either skip items or shift their bubbling by one row after a skipped question.
What to do instead
Answer every question-guess if needed. Bubble in blocks of five and check that the question number matches the bubble row. Use a two-pass strategy: answer all items you can do quickly, mark hard ones, then return; reserve the last two minutes to confirm no blanks and no misalignment.