Year 8 Maths Revision Guide: Data, Algebra, and Geometry

Vocabulary practice flashcards covering fundamental concepts in data analysis, ratios and rates, percentages, linear equations, indices, coefficients, like terms, and angle relationships.

Mean

A measure of center calculated by adding all values and dividing by the total number of values.

Median

The middle value obtained after ordering the values; if there is an even number of values, it is the average of the two middle values.

Mode

The most frequent value in a dataset.

Range

The difference between the highest and lowest values, calculated as $\text{biggest} - \text{smallest}$.

Outlier

A value that is unusually far from the rest of the data values.

Categorical Data

Data described by categories or names.

Discrete Data

Data consisting of countable whole numbers.

Continuous Data

Measured values that often include decimals.

Primary Data

Data that you collect yourself.

Secondary Data

Data that someone else has collected.

Frequency

The number of times a particular value occurs.

Stem-and-leaf Plot

A display that organizes numbers by place value, such as $1|2\ 4\ 7$ representing the values $12$, $14$, and $17$.

Dot Plot

A visual display where each dot represents an observation.

Histogram

A graph for grouped numerical or continuous data in which the bars touch.

Frequency Polygon

A graph constructed by joining class midpoints with straight lines.

Rates

Comparisons of different units, such as $\text{km/h}$ or dollars per item.

Pie Chart

A circular statistical graphic representing a full circle of $360^\circ$, where the angle for each sector is calculated as $\text{category} \div \text{total} \times 360^\circ$.

Gradient ($m$)

The number multiplying $x$ in the linear form $y = mx + b$, representing the rate of change found by $\text{change in } y \div \text{change in } x$.

y-intercept ($b$)

The constant number at the end of the linear equation $y = mx + b$, representing the point where the line crosses the y-axis.

Index (Exponent)

A number indicating how many times the base is multiplied by itself.

Coefficient

The number multiplying a variable in an algebraic term.

Like Terms

Terms that contain the same variable with the same power.

Right Angle

An angle that measures exactly $90^\circ$.

Straight Angle

An angle that measures exactly $180^\circ$.

Full Turn

A complete rotation that measures $360^\circ$.

Complementary Angles

Two or more angles whose sum is equal to $90^\circ$.

Supplementary Angles

Two or more angles whose sum is equal to $180^\circ$.

Vertically Opposite Angles

Opposite angles formed by the intersection of two straight lines; they are always equal.

Isosceles Triangle

A triangle with two equal sides and equal opposite angles.

Equilateral Triangle

A triangle in which all three sides are equal and all three interior angles measure $60^\circ$.

Exterior Angle of a Triangle

An angle formed outside a triangle that is equal to the sum of the two opposite interior angles.

Corresponding Angles

Angles located in the same relative position at each intersection where a straight line crosses parallel lines; they are equal.

Alternate Angles

Angles that form a Z shape between parallel lines; they are equal.

Co-interior Angles

Angles that form a C shape on the interior side of parallel lines; their sum is $180^\circ$.