Grade-8 Mathematics Practice Review

22 question-and-answer flashcards summarizing key math concepts from the practice test, including estimation, angle relationships, algebraic translation, probability, statistics, scientific notation, and proportional reasoning.

How do you estimate the total cost of one soccer, baseball, basketball, football, and volleyball by rounding each individual price to the nearest whole dollar first?

Round the prices ($4.99→$5, $1.46→$1, $12.54→$13, $8.89→$9, $6.43→$6) and add: $5+$1+$13+$9+$6 ≈ $34.

What is the relationship among the three interior angles of any triangle?

Their measures always add to 180°.

Which equation models: “Marty has $80, spends $56 on a shirt, and then buys x boxes of darts at $6 each”?

80 = 56 + 6x

What kind of angle pair are ∠1 and ∠4 when two lines intersect?

Vertical angles—always congruent.

Translate into an algebraic expression: “4 less than twice a number n.”

2n − 4

If four bowling scores have a mean of 136 and a new score of 126 is added, does the 5-week mean increase, decrease, or stay the same?

It decreases (drops from 136 to 134).

Why is a circle graph showing club 45 %, sports 60 %, and music 75 % misleading?

The sectors total 180 %, which is impossible for a whole (100 %) circle and misrepresents the data.

Evaluate 12 + 2(12÷3)² using order of operations.

12 + 2(4)² = 12 + 2·16 = 44.

What is the probability of rolling a 6 on a fair six-sided die two times in a row?

(1/6) × (1/6) = 1/36.

Solve the inequality 6 − 4x ≤ 26.

x ≥ −5 (divide by −4 and reverse the inequality sign).

State the Pythagorean Theorem.

For right triangles, a² + b² = c², where c is the hypotenuse.

How can you verify four plotted points form a square on a coordinate grid?

Show all four sides are equal in length and adjacent sides are perpendicular (slopes are negative reciprocals).

Which measure of central tendency (mean, median, mode, range) is least affected by an extreme outlier?

The median.

If two parallel lines are cut by a transversal, what is true of a pair of supplementary angles?

Their measures add to 180° (e.g., same-side interior angles).

Translate into an expression: “The sum of a number n and 5 is subtracted from 8.”

8 − (n + 5)

Solve for w if 0.8w = 4.

w = 5

How do you find a missing side of a rectangle similar to another rectangle?

Set up a proportion with corresponding sides and solve for the unknown value.

Write 0.5600 in scientific notation.

5.6 × 10⁻¹

Solve 3(x − 4) = −21.

x = −3

How do you find the probability of an event NOT happening?

1 − P(event) or (total favorable outcomes)/(total outcomes) for the complement.

Johnny runs 16 laps of 400 m each. Which arithmetic operation finds the total distance?

Multiply: 400 m × 16 = 6400 m.

What is the simplified ratio of 1560 miles to 60 gallons of gas?

26 : 1 (or 26 miles per gallon).