Maths Terms for 11-13 Yr Olds

1. A part to whole comparison. Example: Where £20 is shared between two people in the ratio 3:5, the first receives £7.50 which is 3/8 of the whole £20. This is his proportion of the whole.

2. If two variables x and y are related by an equation of the form y = kx, then y is directly proportional to x; it may also be said that y varies directly as x. When y is plotted against x this produces a straight line graph through the origin. If two variables x and y are related by an equation of the form y = then y is inversely proportional to x; it may be said that y varies inversely as x.

One of the four regions into which a plane is divided by the x and y axes in the Cartesian co-ordinate system.

A common property or connection between two or more variables. Example: in a linear graph of the form y = 2x, there is a linear relationship between x and y. For every x, y is half the size. Compare with 'correlation'.

1. A line that touches a curve at one point only.

2. A trigonometric function (more on these at GCSE level).

A mathematical statement derived from previously accepted premises and established by means of a proof. A 'theory' is slightly different - this is a testable model that can be used to make predictions, but isn't yet proven.

Not changing; remaining constant. Uniform acceleration, for example, would be to increase speed at a constant rate. Gravitational acceleration on Earth is uniform up to the point of terminal velocity- a falling body gains an extra 9.8 metres per second of speed every second.

A quantity that has magnitude and direction, for example displacement. Displacement (for example one metre North) combines a scalar quantity (distance displaced) with a direction to make a vector quantity.

One-dimensional, two-dimensional, three-dimensional. One-dimensional: able to be identified by one co-ordinate, for example points on a line.

Two-dimensional: requiring two co-ordinates for identification, for example points in a plane. Also used to describe flat geometric shapes.

Three-dimensional: requiring three co-ordinates for identification, for example points in space. Also used to describe solid geometric shapes

An angle between zero and ninety degrees.

Where two straight lines are cut by a third, as in the diagrams, the angles d and f (also c and e) are alternate.