Maths Terms for 11-13 Yr Olds

A unit of measurement system historically used in the United Kingdom and other English speaking countries. Units include inch, foot, yard, mile, acre, ounce, pound, stone, ton, pint, quart and gallon. Now largely replaced by metric units.

An improper fraction has a numerator that is greater than its denominator. Example: 9/4 is improper and could be expressed as the mixed number 2 1/4.

Symbol: in. An imperial unit of length. 12 inches = 1 foot. 36 inches = 1 yard. 

Statements such as b > c are inequalities.

They differ from equations in that they don't have equals signs and don't have fixed solutions, only boundary solutions. For example in the above it is known that b must be at least greater than c, but how much greater is not known. Boundary solutions to inequalities can be indicated graphically using shading.

Any of the positive or negative whole numbers and zero. Examples: -2, -1, 0, +1, +2. As opposed to decimal numbers.

The value of the non-zero coordinate of the point where a line on a graph cuts an axis. The y intercept is given the symbol c in straight line graphs of the form y = mx + c.

At a vertex of a polygon, the angle that lies within the polygon.

To have an intersect is to have a common point or points. Examples: Two intersecting lines intersect at a point; two intersecting planes intersect in a line.

Operations that, when they are combined, leave the entity on which they operate unchanged. Examples: addition and subtraction are inverse operations e.g. 5 + 6 - 6 = 5. Multiplication and division are inverse operations e.g. 6 × 10 / 10 = 6.

Some operations, such as reflection in the x-axis, are self-inverse.

A number that is not an integer and cannot be expressed as a common fraction with a non-zero denominator. Real irrational numbers, when expressed as decimals, are infinite, nonrecurring decimals.

Examples: the square root of three. Pi is also an irrational number.