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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.

Reviewed Cantonese equivalent not yet available.Factorization 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.

Reviewed Cantonese equivalent not yet available.Six is the greatest common factor of eighteen and twenty-four.
423difference of squaresnoun
Study

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.

Reviewed Cantonese equivalent not yet available.The difference of squares x squared minus sixteen factors into two binomials.
424perfect square trinomialnoun
Study

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.

Reviewed Cantonese equivalent not yet available.The expression x squared plus six x plus nine is a perfect square trinomial.
425radical expressionnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The radical expression square root of fifty simplifies to five square root of two.
426rational expressionnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The rational expression is undefined when its denominator equals zero.
427absolute-value equationnoun
Study

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.

Reviewed Cantonese equivalent not yet available.The absolute-value equation has solutions two units on either side of five.
428compound inequalitynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The compound inequality describes all values between negative one and four.
429interval notationnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The solution x greater than three is written in interval notation with a parenthesis at three.
430coordinate pairnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The coordinate pair negative two, five lies in the second quadrant.
431direct proportionnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Distance and time are in direct proportion when speed remains constant.
432inverse proportionnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.For a fixed trip, speed and travel time are in inverse proportion.
433slope-intercept formnoun
Study

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.

Reviewed Cantonese equivalent not yet available.Slope-intercept form displays a line's slope and vertical intercept directly.
434point-slope formnoun
Study

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.

Reviewed Cantonese equivalent not yet available.Point-slope form makes it easy to write the equation from a point and a slope.
435standard formnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The equation was rewritten in standard form with integer coefficients.
436system of inequalitiesnoun
Study

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.

Reviewed Cantonese equivalent not yet available.The solution to the system of inequalities is the overlapping shaded region.
437linear inequalitynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The linear inequality includes points above the dashed boundary.
438exponential growthnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Compound interest produces exponential growth.
439exponential decaynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Radioactive material undergoes exponential decay.
440percent changenoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The price rose from forty to fifty dollars, a percent change of twenty-five percent.
441depreciationnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The car's depreciation was steepest during its first year.
442conditional probabilitynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The conditional probability of rain changes when dark clouds are already present.
443permutationnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Each different ordering of the three books is a permutation.
444combinationnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Choosing three committee members from ten is a combination.
445sample surveynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The sample survey contacted randomly selected households.
446observational studynoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The 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.

Reviewed Cantonese equivalent not yet available.The controlled experiment assigns plants to different light levels.
448population parameternoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The true average height of all trees in the forest is a population parameter.
449sample statisticnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.The sample mean is a sample statistic used to estimate the population average.
450mean absolute deviationnoun
Study

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.

Reviewed Cantonese equivalent not yet available.A 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.

Reviewed Cantonese equivalent not yet available.Population 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.

Reviewed Cantonese equivalent not yet available.A z-score of two places the value two standard deviations above the mean.
453normal distributionnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.Adult measurement data often approximate a normal distribution.
454skewnessnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.A few very high incomes create positive skewness.
455correlation coefficientnoun
Study

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

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

Reviewed Cantonese equivalent not yet available.A 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.

Cantonese 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.