Maths Terms for 11-13 Yr Olds

A subset of a population. By carrying out a random survey of some school pupils for example, the pupils you survey would make up the sample, and all the pupils in that school would make up that population.

In statistics, samples are used to make inferences (estimated conclusions) about a larger population without having to survey the whole population.

Scalar quantities have magnitude (size) but no direction. Temperature, for example, is a scalar. This sets them apart from vectors, which have size and direction (for example gravitational attraction, which acts towards the centre of a mass (mostly the Earth) and varies in size depending how far you are from the Earth). 

A measuring device usually consisting of points on a line with equal intervals. Examples: a ruler is a type of scale, as is an axis on a graph.

For two similar geometric figures, the ratio of corresponding edge lengths.

A triangle with no two sides equal and consequently no two angles equal.

A graph on which paired observations are plotted and which may indicate a relationship between the variables. Example: The heights of a number of people could be plotted against their arm span measurements. If height is roughly related to arm span, the points that are plotted will tend to lie along a line.

A plane geometrical configuration formed by cutting a solid figure with a plane. Example: A section of a cube could be a triangle, quadrilateral, pentagon or hexagon according to the direction of the plane cutting it.

The region within a circle bounded by two radii and one of the arcs they cut. Example:

The smaller of the two sectors is the minor sector and the larger one the major sector.

1. The part of a line between two points.

2. Within a circle, the region bound by an arc and the chord joining its two end points.

The smaller of the two regions, is the minor segment and the larger is the major segment.

A succession of terms formed according to a rule. There is a definite relation between one term and the next or between each term and its position in the sequence. Example: for the sequence 1, 4, 9, 16, 25 etc., each term is the square of number of the term's position in the sequence.

A well-defined collection of objects or numbers (themselves then called called members or elements).

A drawing instrument for constructing parallel lines, perpendicular lines and certain angles.

The run of digits in a number that is needed to specify the number to a required degree of accuracy. Additional zero digits may also be needed to indicate the number's magnitude. Examples: To the nearest thousand, the numbers 125 000, 2 376 000 and 22 000 have 3, 4 and 2 significant figures respectively; to 3 significant figures 98.765 is written 98.8

A geometric figure is similar to another if it is congruent to an enlargement of the other. Any two squares are similar, as are any two circles.

A fraction where the numerator and denominator are both integers. Also known as a common or vulgar fraction.

A closed surface, in three-dimensional space, consisting of all the points that are a given distance from a fixed point, the centre. A hemi-sphere is a half-sphere. Adjective: spherical.

In geometry, a 2D quadrilateral with four equal sides and four internal angles that are all right angles.

A number that can be expressed as the product of two equal numbers. Example 36 = 6 x 6 and so 36 is a square number.

A format for displaying grouped data. Class intervals form the stem and all observations are listed in order against them, forming the leaves. The numbers 29, 16, 18, 8, 4, 16, 27, 19, 13, 15 could be displayed as:

The 'class interval' is the tens digit of the numbers. The diagram resembles a histogram on its side.

Where a population has been divided into strata based on common characteristics, a random sample drawn from each of the strata. Example: for the purposes of a school survey the pupils might be divided into age groups. The size of the sample drawn at random from each age group might be proportional to the relative sizes of the different age group for greater precision.

An expression including one or more square roots (or cube roots, fourth roots, etc.)

A set of points defining a space in two or three dimensions.

A plane figure has symmetry if it is invariant under (unchanged after) a reflection or rotation i.e. if the effect of the reflection or rotation is to produce an identical-looking figure in the same position. See also reflection symmetry, rotation symmetry. Adjective: symmetrical.