FAST common mistakes
FAST · Understand the traps and how to avoid them.
On a Key Ideas and Details question, the student selects an answer choice that is factually true according to the passage but does not actually answer the question asked (e.g., the question asks why a character acted, and the student picks a choice describing where the character went).
Students read the passage first and then skim the question, so they recognize familiar words in an answer choice and stop there. The choice feels 'right' because it is verifiable in the text, and the student never checks it against the specific question stem.
What to do instead
Before looking at the choices, restate the question in the student's own words and underline its key verb and subject ('why did she leave?'). Then test every choice against that restated question: a choice that is accurate but off-question gets crossed out, not kept. Practice with sets where two distractors are true-but-irrelevant.
The student answers inference questions using background knowledge about the topic rather than evidence in the passage, choosing the option that matches what they already know about science or history instead of what the text actually implies.
Informational passages on familiar topics trigger prior knowledge, and confident students assume the passage agrees with what they already believe. Inference questions feel like recall questions, so the student never goes back to locate supporting lines.
What to do instead
Require a line-number or quoted phrase as proof for every inference choice before marking it. If no sentence in the passage supports the choice, eliminate it even if it is true in real life. Do inference drills where the correct answer contradicts common prior knowledge, to break the habit.
On Craft and Structure questions, the student identifies an author's purpose or tone from the passage's topic rather than from the words actually used - for example, labeling any text about pollution as 'persuasive' or any poem about nature as 'joyful' regardless of the language.
Students conflate subject matter with purpose. Theme and topic are easier to spot than tone, so the student substitutes the easy judgment for the required one and does not slow down to examine word choice, punctuation, or structural shifts.
What to do instead
Circle charged adjectives and verbs and label each as positive, negative, or neutral before choosing purpose or tone. Note where the text shifts (a 'but,' a new stanza, a question) and ask what that shift is doing. Then match the accumulated evidence to a purpose word from a short, memorized list (inform, explain, persuade, entertain, compare, criticize).
When a question pairs two passages, the student chooses an answer supported by only one of the texts, or assumes the two authors agree because they discuss the same topic.
The student reads the passages sequentially and answers from the stronger memory, usually the second or the more engaging one. Comparison requires holding both texts at once, which unmotivated readers do not do, and the answer choices are designed so that one-sided options look complete.
What to do instead
On any paired-passage set, draw a two-column chart labeled with each passage and jot one main point per column before answering. For 'both' questions, put a check in both columns only when each text supports the choice; an option with a check in one column is eliminated. Physically cover the passages when checking choices so the answer must come from the notes.
The student picks the most common everyday meaning of a multiple-meaning or context-dependent word (e.g., reading 'current' as a flow of water in a passage about electricity, or 'table' as furniture in a passage about data).
The dominant meaning is retrieved automatically and feels correct before context is processed. Students also skip the sentence around the word and rely on the word in isolation, which is exactly what the test designers anticipate.
What to do instead
Substitute each candidate meaning into the original sentence and read the whole sentence aloud; discard any meaning that breaks the grammar or the surrounding logic. Require the student to point to a context clue (a nearby word, contrast, or example) that justifies the chosen meaning before marking it.
In a text-based writing response, the student either makes a claim with no quoted or paraphrased evidence, or drops in quotations that are never connected back to the claim. The response lists details from the sources without explaining what they prove.
Students treat evidence as decoration rather than argument. They have been taught 'use text evidence' as a rule, so they add quotes to satisfy the rule without understanding that each piece of evidence must be interpreted for the reader.
What to do instead
Use a fixed frame: claim sentence, evidence sentence introduced by the source, then an explanation sentence beginning 'This shows that...' or 'This matters because...'. Enforce the rule that every quotation must be followed by at least one sentence of the student's own commentary, and check each paragraph has both evidence and explanation before moving on.
The student misplaces the decimal point when multiplying or dividing decimals, or rounds too early in a multi-step computation, producing an answer that is off by a factor of ten or by a small amount that a quick estimate would have caught.
Students apply digit-counting rules mechanically without understanding magnitude, and they treat estimation as optional extra work. Under time pressure they skip the reasonableness check entirely, so an impossible answer survives to the answer sheet.
What to do instead
Before computing, estimate the answer with rounded numbers and write the estimate next to the problem. After computing, compare the result to the estimate and refuse to bubble an answer that differs by a factor of ten or more. For decimal placement, count decimal places in the factors and confirm with the estimate rather than counting alone.
When solving a linear equation, the student performs an operation on only one side (e.g., subtracting 5 from the left side of 3x + 5 = 20 but not from the right), or moves a term without changing its sign.
Students memorize a sequence of moves ('get x by itself') without the underlying balance model, so the operation feels like an edit to one expression rather than to an equation. Sign errors go unnoticed because the student never substitutes the answer back in.
What to do instead
Write each step as a full equation with the same operation shown on both sides, and keep the equals signs vertically aligned so imbalance is visible. Always substitute the solution into the original equation and check both sides are equal before selecting an answer.
The student substitutes the diameter for the radius in circle formulas, or applies an area formula to a perimeter question (and vice versa), often also ignoring whether the answer should be in square or linear units.
Formula recall is fragile and the two circle formulas look similar. Students grab the first formula that comes to mind and plug in the most prominent number on the diagram without checking what that number represents.
What to do instead
Annotate the figure before computing: label the radius explicitly, and if only the diameter is given, write 'r = d ÷ 2' as a separate step. Copy the formula from a reference sheet and match its variables to the labels one at a time. Check that the unit of the answer matches the quantity asked (square units for area, linear for perimeter).
The student misreads the scale on a graph or the row and column headers on a table - assuming each gridline represents one unit when it represents five, or reading a value from the wrong category - and then computes correctly from the wrong numbers.
Readers default to a one-to-one assumption about gridlines and skim axis labels because they appear to be decoration. The arithmetic then feels right, so no alarm goes off, especially on questions about mean, median, or range where the error propagates silently.
What to do instead
Before answering any data question, state aloud the value of one gridline and write the axis scale at the top of the workspace. Trace from the correct bar or point to the axis with a finger or pencil, and circle the row and column headers being used. Verify the total against a rough visual estimate of the graph.