Maths Terms for 11-13 Yr Olds

Symbol: mm. One thousandth of a metre.

The name for the symbol -, which represents the operation of subtraction.

Unit of time. One-sixtieth of an hour. 1 minute = 60 seconds.

In the measurement of angles, 1/60 of a degree is also known as a minute.

A whole number and a fractional part expressed as a common fraction.

Example: 1 2/3 (one and two thirds) is a mixed fraction. Also known as a mixed number.

The most common value in a set of data. For example in 2, 3, 3, 3, 3, 2, the modal value would be 3. If no value is repeated, no mode exists.

In some situations the mode could be thought of as the most appropriate 'average' value for the data, e.g. in samples involving whole numbers or quantities (the mean, as opposed to mode, will usually give a decimal number).

For any integers a and b, a is a mulitple of b if a third integer exists such that a = b x c.

Example: 14 = 7 x 2, 49 = 7 x 7 and 70 = 7 x 10. So 14, 49 and 70 are all multiples of 7.

-21 is also a multiple of 7 since -21 = 7(-3).

The operation of combining two numbers to give a third number, the product. Example: 12 x 3 = 36 is a multiplication. Multiplication can be seen as the process of repeated addition.

Example: 3 x 5 = 3 + 3 + 3 + 3 + 3 = 15.

Multiplication is the inverse operation of division, and it follows that 7 ÷ 5 × 5 = 7.

A number less than zero. Example: -0.25. Where a point on a line is labelled 0 and equally spaced points to one side of it are labelled -1, -2, -3 etc, these, and the numbers represented by points between them, are negative numbers.

Negative numbers can also be used to represent direction, for example when describing the velocity (speed and direction) of a projectile. If a ball hits a wall and is said to move at 20 metres per second and then -2 metres per second, this just means that at some point it moves in the opposite direction it started moving (i.e. it bounces back off the wall at a speed of 2 metres per second.

1. In geometry, a plane figure in 2D composed of polygons which by folding and joining can form a 3D polyhedron.

2. Adjective meaning 'remaining after deductions'. Example: for businesses net profit is their profit after deducting all operating costs and expenses.

Any convention for recording mathematical ideas in writing and symbols. Example: Money is recorded using decimal notation e.g. £2.50.