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9th-grade-vocabulary-words

English Vocabulary · Grade 9 Live Review Preview

9th Grade Vocabulary Words

Ninth grade marks the transition to high-school reading and writing across literature, argument, research, biology, physical and Earth science, algebra, computing, world history, civics, and geography. This level develops precise academic and domain-specific vocabulary while strengthening context, nuance, source evaluation, figurative language, and evidence-based communication.

This independently authored 800-word beta curriculum is arranged in twenty-three pages of up to thirty-five words. Pages containing words 1–500 include five cloze questions drawn only from that enhanced range; words 501–800 remain fully visible and editable as list pages while the expanded practice layer is developed. Each row includes a subject-field label and an editable word-study note about a transparent affix, compound structure, capitalization, or dictionary base form. The cited Grade 9 resources calibrate difficulty and study skills only; all learner-facing definitions, examples, quizzes, and descriptions are original KSSR copy.

Please note: the vocabulary lists for grades 9~11 have been selected to ensure no overlap with the previous grade level. If the words are too specialized or difficult for you, please go back to grade levels 4~8 and review the words on those pages.

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800 words
Words 421–455 of 800
#WordDetailsMeaningSample sentence
421factorizationnoun
Study

Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Suffix focus: -ization forms a noun for a process of making or becoming.

AutorFactorization changes x squared minus nine into the product of x minus three and x plus three.
422greatest common factornoun
Study

Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: greatest + common + factor. Study the complete expression as one field-specific unit.

größter gemeinsamer FaktorSix is the greatest common factor of eighteen and twenty-four.
423difference of squaresnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: difference + of + squares. Study the complete expression as one field-specific unit.

Differenz der QuadrateThe difference of squares x squared minus sixteen factors into two binomials.
424perfect square trinomialnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: perfect + square + trinomial. Study the complete expression as one field-specific unit.

perfektes quadratisches TrinomThe expression x squared plus six x plus nine is a perfect square trinomial.
425radical expressionnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: radical + expression. Study the complete expression as one field-specific unit.

radikaler AusdruckThe radical expression square root of fifty simplifies to five square root of two.
426rational expressionnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: rational + expression. Study the complete expression as one field-specific unit.

rationaler AusdruckThe rational expression is undefined when its denominator equals zero.
427absolute-value equationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: absolute + value + equation. Study the complete expression as one field-specific unit.

AbsolutwertgleichungThe absolute-value equation has solutions two units on either side of five.
428compound inequalitynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: compound + inequality. Study the complete expression as one field-specific unit.

zusammengesetzte UngleichheitThe compound inequality describes all values between negative one and four.
429interval notationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: interval + notation. Study the complete expression as one field-specific unit.

IntervallnotationThe solution x greater than three is written in interval notation with a parenthesis at three.
430coordinate pairnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: coordinate + pair. Study the complete expression as one field-specific unit.

KoordinatenpaarThe coordinate pair negative two, five lies in the second quadrant.
431direct proportionnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: direct + proportion. Study the complete expression as one field-specific unit.

direkter AnteilDistance and time are in direct proportion when speed remains constant.
432inverse proportionnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: inverse + proportion. Study the complete expression as one field-specific unit.

umgekehrtes VerhältnisFor a fixed trip, speed and travel time are in inverse proportion.
433slope-intercept formnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: slope + intercept + form. Study the complete expression as one field-specific unit.

Steigungs-AchsenabschnittsformSlope-intercept form displays a line's slope and vertical intercept directly.
434point-slope formnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: point + slope + form. Study the complete expression as one field-specific unit.

Punkt-SteigungsformPoint-slope form makes it easy to write the equation from a point and a slope.
435standard formnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: standard + form. Study the complete expression as one field-specific unit.

StandardformThe equation was rewritten in standard form with integer coefficients.
436system of inequalitiesnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: system + of + inequalities. Study the complete expression as one field-specific unit.

System der UngleichheitenThe solution to the system of inequalities is the overlapping shaded region.
437linear inequalitynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: linear + inequality. Study the complete expression as one field-specific unit.

lineare UngleichungThe linear inequality includes points above the dashed boundary.
438exponential growthnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: exponential + growth. Study the complete expression as one field-specific unit.

exponentielles WachstumCompound interest produces exponential growth.
439exponential decaynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: exponential + decay. Study the complete expression as one field-specific unit.

exponentieller ZerfallRadioactive material undergoes exponential decay.
440percent changenoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: percent + change. Study the complete expression as one field-specific unit.

prozentuale VeränderungThe price rose from forty to fifty dollars, a percent change of twenty-five percent.
441depreciationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Suffix focus: -ation commonly forms a noun naming an action, process, or result.

AbschreibungThe car's depreciation was steepest during its first year.
442conditional probabilitynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: conditional + probability. Study the complete expression as one field-specific unit.

bedingte WahrscheinlichkeitThe conditional probability of rain changes when dark clouds are already present.
443permutationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Suffix focus: -ation commonly forms a noun naming an action, process, or result.

PermutationEach different ordering of the three books is a permutation.
444combinationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Suffix focus: -ation commonly forms a noun naming an action, process, or result.

KombinationChoosing three committee members from ten is a combination.
445sample surveynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: sample + survey. Study the complete expression as one field-specific unit.

RepräsentativerhebungThe sample survey contacted randomly selected households.
446observational studynoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: observational + study. Study the complete expression as one field-specific unit.

BeobachtungsstudieThe observational study compares sleep habits and grades without changing either.
447controlled experimentnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: controlled + experiment. Study the complete expression as one field-specific unit.

kontrolliertes ExperimentThe controlled experiment assigns plants to different light levels.
448population parameternoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: population + parameter. Study the complete expression as one field-specific unit.

BevölkerungsparameterThe true average height of all trees in the forest is a population parameter.
449sample statisticnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: sample + statistic. Study the complete expression as one field-specific unit.

BeispielstatistikThe sample mean is a sample statistic used to estimate the population average.
450mean absolute deviationnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: mean + absolute + deviation. Study the complete expression as one field-specific unit.

mittlere absolute AbweichungA small mean absolute deviation indicates that values cluster near the mean.
451population variancenoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: population + variance. Study the complete expression as one field-specific unit.

PopulationsvarianzPopulation variance increases when observations spread farther from the average.
452z-scorenoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: z + score. Study the complete expression as one field-specific unit.

z-WertA z-score of two places the value two standard deviations above the mean.
453normal distributionnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: normal + distribution. Study the complete expression as one field-specific unit.

1. Normalverteilung 2. Gauß-VerteilungAdult measurement data often approximate a normal distribution.
454skewnessnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Suffix focus: -ness forms a noun naming a quality or state.

die Neigung, die SchrägeA few very high incomes create positive skewness.
455correlation coefficientnoun
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Field: Grade 9 mathematics, computing, and data-literacy term

Word study: Term structure: correlation + coefficient. Study the complete expression as one field-specific unit.

KorrelationskoeffizientA correlation coefficient near zero indicates little linear association.

Vocabulary reading and practice

Planning a Survey

Reading practice for pages 13–15. Five relevant words are highlighted.

English reading

A survey team plots each response as a coordinate pair and calculates a correlation coefficient to describe the linear association. A strong association does not prove direct proportion or causation. The team also uses conditional probability to compare subgroups, then considers every permutation of question order to test whether sequence changes responses.

German translation

A reviewed translation is not available for this passage yet.

Reading comprehension

1. What does the correlation coefficient describe?

It describes the linear association between variables.

2. Does a strong association prove causation?

No, a strong association does not prove causation.

3. Why test each permutation of question order?

The team wants to see whether order changes responses.

Vocabulary quiz

Choose the dictionary equivalent for each of 5 selected words.

Sources and curriculum references

These references guide selection and calibration. Definitions, sample sentences, readings, questions, and teaching notes are independently written and reviewed.