LC Foundation Maths key terms

A whole number greater than 1 whose only positive divisors are 1 and itself, such as 2, 3, 5, 7 or 11. The number 1 is not prime, and 2 is the only even prime.

A whole number that divides another number exactly, with no remainder left over. For example, 1, 2, 3, 4, 6 and 12 are all factors of 12.

The result of multiplying a whole number by any whole number. The multiples of 6 are 6, 12, 18, 24 and so on, continuing without end.

The largest whole number that divides two or more given numbers exactly. The factors shared by 12 and 18 are 1, 2, 3 and 6, so the highest common factor is 6.

The smallest number that is a multiple of two or more given numbers. For 4 and 6 the lowest common multiple is 12, the first value to appear in both multiplication tables.

A fraction or proportion written out of 100 and shown with the % symbol. A score of 45% means 45 out of every 100, which is the fraction 45/100.

The digits of a number that count towards its accuracy, read from the first non-zero digit onwards. Rounding 4.7382 to three significant figures gives 4.74.

A shorthand for very large or very small numbers written as a value between 1 and 10 multiplied by a power of ten, for example 3.2 × 10⁵ for 320 000.

The agreed sequence used to work out a calculation: brackets first, then indices or powers, then multiplication and division, then addition and subtraction, taking each stage from left to right.

A letter or symbol used in place of a number that can change or is not yet known. In the equation 3x + 5 = 20 the variable is x.

The number written in front of a variable that multiplies it. In the term 7y the coefficient is 7, while in −4ab the coefficient is −4.

A mathematical phrase made from numbers, variables and operations that has no equals sign. Examples include 5x − 3, 2(a + b) and x/4 + 1.

A statement saying that two expressions are equal, with an equals sign between them. Solving an equation means finding the unknown value that makes the statement true.

A rule written as an equation that links quantities together, common in geometry and science. For instance, A = πr² gives the area of a circle from its radius.

Terms that contain exactly the same variables raised to the same powers, which means they can be added or subtracted. For example, 4x and −9x combine to give −5x.

A comparison between two expressions using the symbols <, >, ≤ or ≥ rather than an equals sign. For example, x > 5 means x is greater than 5.

A comparison of two or more quantities of the same type, usually written with a colon. A ratio of 3:2 means three parts to every two parts.

A statement that two ratios are equal, or a comparison of a part with the whole. If 8 of 20 students walk to school, the proportion is 8/20 = 0.4.

A relationship in which two quantities increase or decrease together at the same rate, so doubling one doubles the other and their quotient stays constant.

A relationship in which one quantity increases as the other decreases, so their product stays the same. Doubling the number of workers halves the time taken.

The total distance travelled divided by the total time taken, given by speed = distance ÷ time. A car covering 150 km in 3 hours has an average speed of 50 km/h.

Interest calculated on the original amount plus all the interest already added, so the money grows faster each year. It is found by repeated multiplication by the growth factor.

The amount of turn between two straight lines or rays that meet at a point, measured in degrees. A right angle is 90°, a straight line is 180° and a full turn is 360°.

A rule for right-angled triangles: the square of the hypotenuse equals the sum of the squares of the other two sides, written a² + b² = c².

The amount of flat surface covered by a two-dimensional shape, measured in square units such as cm². The area of a rectangle is its length multiplied by its width.

The distance all the way around the outside edge of a circle, found using π × diameter or 2πr. It is the perimeter of the circle.

The amount of space a three-dimensional object takes up, measured in cubic units such as cm³. For a cuboid, volume equals length × width × height.

Describing two shapes that are exactly the same size and shape, even if one has been rotated, reflected or moved. All matching sides and angles are equal.

The ratio that links a length on a map or drawing to the real length it stands for. On a scale of 1:50 000, one centimetre represents 50 000 centimetres on the ground.

The average of a set of values, found by adding them all and dividing by how many there are. For 2, 5, 8 and 9 the mean is 24 ÷ 4 = 6.

The middle value of a data set once the values are listed in order. When there is an even number of values, the median is the mean of the two middle ones.

The value that appears most frequently in a set of data. A data set may have one mode, two modes, or no mode if every value occurs equally often.

A simple measure of spread found by subtracting the smallest value in a data set from the largest. It shows how widely the data is stretched.

The number of times a particular value or category occurs in a set of data, often recorded with tally marks and then totalled in a frequency table.

A graph that plots pairs of values as points on axes to show whether two variables are linked, with patterns described as positive, negative or no correlation.

A measure between 0 and 1 of how likely an event is, where 0 means impossible and 1 means certain. It can be given as a fraction, decimal or percentage.

The full list or diagram of every possible outcome of an experiment. For a single roll of a fair die, the sample space is 1, 2, 3, 4, 5 and 6.

Events that cannot both happen in the same trial, such as rolling an odd number and rolling a six on one die. Their probabilities can be added together.

Events where the result of one does not affect the result of the other, such as separate tosses of a coin. The probability of both happening is found by multiplying.