Grade 8 Mathematics - Units 1-4 Vocabulary Review

This set of flashcards covers critical mathematical terminology and definitions across the first four units of the Grade 8 curriculum, including rational number operations, powers and roots, coordinate systems, and geometric similarity.

Rational Numbers

Numbers that can be written in the form of $\frac{a}{b}$ where $a$ and $b$ are integers and $b \neq 0$.

Proper Fraction

A fraction in which the numerator is less than the denominator.

Improper Fraction

A fraction in which the numerator is greater than or equal to the denominator.

Mixed Fraction

An improper fraction expressed as a whole number and a proper fraction.

Opposite Numbers

Two rational numbers that have the same distance from $0$ but are on different sides of $0$ on a number line.

Set

A collection of items, where the items are referred to as elements.

Venn Diagram

A diagram that uses intersecting circles to show relationships among sets of numbers.

Absolute Value

The distance from zero that a number is on a number line without considering direction, denoted by $|x|$.

Reciprocal

A number that when multiplied by the original number results in a product of $1$; also known as the multiplicative inverse.

Principal (P)

The amount of money that is borrowed or loaned.

Interest (I)

A payment for the use of money or the profit return on an investment.

Simple Interest

The interest paid on the original principal during the whole interest periods, calculated using the formula $I = PRT$.

Squaring

The process of multiplying a number by itself.

Perfect Square

A rational number $q$ such that $q = x^{2}$ for some rational number $x$.

Square Root

For any two rational numbers $x$ and $y$, if $x^{2} = y$, then $x$ is the square root of $y$.

Radical Sign

The symbol $\sqrt{}$ used to indicate the principal square root.

Radicand

The expression under the radical sign in a square root or cube root operation.

Cubing

The process of multiplying a number by itself three times.

Perfect Cube

A rational number $n$ such that $n = m^{3}$ for some rational number $m$.

Cube Root

One of three identical factors whose product is the given number, denoted by $\sqrt[3]{a}$.

Cartesian Coordinate Plane

A plane formed by two intersecting perpendicular number lines called the $x$-axis and the $y$-axis.

Origin

The point where the horizontal $x$-axis and the vertical $y$-axis intersect.

Abscissa

The first coordinate in an ordered pair $(x, y)$, also referred to as the $x$-coordinate.

Ordinate

The second coordinate in an ordered pair $(x, y)$, also referred to as the $y$-coordinate.

Quadrants

The four regions into which the coordinate axes divide the plane.

Inequality

A mathematical sentence containing relation signs such as $<$, $>$, $\leq$, $\geq$, or $\neq$.

Equivalent Inequalities

Any two inequalities that share the same solution set.

Similar Figures

Two figures that have the same shape but not necessarily the same size.

Scale Factor

The ratio of two corresponding sides of similar polygons, also known as the constant of proportionality ($k$).