NPOST cheat sheet

Order of operations: evaluate parentheses, then exponents, then multiplication and division left to right, then addition and subtraction left to right.

Percent change = (new − old) ÷ old × 100; a positive result is an increase, a negative result a decrease.

Percent of a number: part = rate × whole, so 15% of 80 = 0.15 × 80 = 12.

Mean = sum ÷ count; median = middle value of an ordered list (average the two middle values if the count is even).

Area formulas: rectangle A = lw, triangle A = ½bh, circle A = πr²; circumference C = 2πr.

Slope of a line through (x₁,y₁) and (x₂,y₂) is m = (y₂ − y₁) ÷ (x₂ − x₁).

To add or subtract fractions, rewrite over a common denominator; to multiply, multiply numerators and denominators directly.

Ratio a:b means a/b; scale up by multiplying both terms by the same nonzero number.

Main idea = the central point covering the whole passage; a supporting detail covers only one part.

An inference must be logically forced by stated evidence, not merely plausible or personally familiar.

Tone is the author's attitude (e.g., critical, neutral, enthusiastic); mood is the feeling created in the reader.

'According to the passage' questions require text-based answers; 'the author implies' questions require a supported inference.

Cause-and-effect signal words include because, therefore, thus, consequently, and as a result.

Contrast signal words include however, although, nevertheless, whereas, and on the other hand.

Chronological order is signaled by dates, times, and sequence words such as first, then, and finally.

A valid summary restates the main idea and key support in condensed form without adding new claims.

A subject and its verb must agree in number; intervening prepositional phrases do not change the subject's number.

Indefinite pronouns each, either, neither, everyone, and nobody are singular and take singular verbs.

Collective nouns (team, jury, committee) take a singular verb when the group acts as one unit.

Use who for subjects and whom for objects; use I for subjects and me for objects.

A pronoun must agree with its antecedent in number and gender, and must refer to one clear antecedent.

Commas set off nonessential clauses; essential (restrictive) clauses take no commas.

Avoid comma splices: join two independent clauses with a semicolon, a coordinating conjunction, or a period.

Use the comparative (-er, more) for two items and the superlative (-est, most) for three or more.

Every incident report records who, what, when, where, how, and who was involved or notified.

Write in past tense and third person; avoid first-person opinion and emotional language.

Use objective, factual wording: 'The officer observed' rather than 'the officer felt' or 'probably'.

Report only what was directly observed or reliably reported; attribute secondhand information to its source.

Quote speech verbatim in quotation marks; do not paraphrase statements as if they were direct quotes.

Record exact times, dates, locations, names, badge or ID numbers, and injuries or property damage in specific terms.

Use chronological order; state facts and observations separately from conclusions or recommendations.

Do not omit unfavorable facts; completeness and accuracy take priority over brevity.

A complete sentence needs a subject, a predicate, and a complete thought; a fragment lacks one of these.

A run-on joins independent clauses without correct punctuation or conjunction; fix with a period, semicolon, or conjunction.

Transitions show relationships: addition (also, moreover), contrast (however, yet), cause (therefore, because).

Active voice: subject performs the action; passive voice: subject receives it (was written by).

Parallel structure requires items in a list to share the same grammatical form.

Apostrophes mark possession (officer's report) or contraction (it's = it is); its is possessive.

A paragraph develops one controlling idea, usually stated in a topic sentence and supported by details.

Proofread for spelling, capitalization, and agreement; proper nouns and sentence beginnings are capitalized.

Distance = rate × time; rearrange to rate = distance ÷ time and time = distance ÷ rate.

Perimeter of a rectangle = 2l + 2w; perimeter of a square = 4s.

Convert a fraction to a decimal by dividing numerator by denominator; convert decimal to percent by multiplying by 100.

Scientific notation: a × 10ⁿ, where 1 ≤ a < 10; move the decimal left for positive exponents, right for negative.

Probability of an event = favorable outcomes ÷ total possible outcomes.

To solve a proportion a/b = c/d, cross-multiply: ad = bc.

Volume of a rectangular solid = length × width × height.

A fact can be verified; an opinion expresses a judgment, belief, or feeling.

The topic is what the passage is about; the main idea is the claim the author makes about that topic.

Context clues for an unfamiliar word include definition, example, contrast, and cause-effect relationships in nearby sentences.

An author's purpose is usually to inform, persuade, entertain, or explain a process.

A claim needs supporting evidence; an unsupported assertion is not evidence.

When comparing two passages, identify shared topic first, then note differences in purpose, tone, or evidence.

Sequence questions: locate the events in the text, then order them by the stated time markers.

Eliminate answer choices that are too broad, too narrow, or contradicted by the passage.

Use a colon after a complete sentence to introduce a list or explanation, not after a verb or preposition.

Use a semicolon between closely related independent clauses and before conjunctive adverbs like however or therefore.

Use dashes or parentheses for parenthetical (nonessential) material that interrupts the sentence.

Prepositions take object pronouns: between you and me, not between you and I.

Avoid dangling modifiers: the introductory phrase must describe the subject that follows it.

Use fewer for countable items and less for uncountable quantities.

Use lay (to place something) with an object and lie (to recline) without one.

Quotation marks enclose exact words; periods and commas go inside closing quotation marks in standard American usage.

A report heading typically includes case or report number, date and time of occurrence, location, and reporting officer.

The narrative section states the sequence of events; the disposition section states the outcome or action taken.

Describe persons by name, role, and identifiers rather than by opinion or speculation about character.

Use precise measurements and counts (approximate distances, estimated values) rather than vague terms like 'a lot'.

Document evidence handling: what was collected, by whom, and where it was stored.

Note witnesses and contact information, and record whether medical aid or additional units were requested.

Avoid jargon, abbreviations, and codes that a general reader or reviewer would not understand.

Use neutral terms such as 'stated' or 'reported' instead of 'claimed' or 'admitted', which imply judgment.

Subject-verb-object is the default clear sentence order; place modifiers near the word they modify.

Vary sentence length and structure to maintain readability; avoid strings of short, choppy sentences.

Use concrete nouns and strong verbs; replace vague words like 'thing' or 'got' with specific terms.

A pronoun must have one clear antecedent; repeat the noun if ambiguity results.

Keep verb tense consistent within a paragraph unless the time frame changes.

Use a dictionary or style guide to confirm spelling and word choice rather than guessing.

Outlines organize writing: main points become topic sentences, supporting details become body sentences.

Revise for content and organization first, then edit for grammar, then proofread for mechanics.