LANTITE Numeracy key terms

The value a digit has because of its position in a number; in 3472 the 4 means four hundreds, while the 3 means three thousands.

A whole number that divides another whole number exactly, leaving no remainder; 1, 2, 3, 4, 6 and 12 are all factors of 12.

The result of multiplying a number by a whole number; the multiples of 7 include 7, 14, 21 and 28.

A whole number greater than 1 whose only factors are 1 and itself, such as 2, 3, 5, 7 and 11.

Fractions that name the same amount even though the numbers differ, such as one half and two quarters; multiplying top and bottom by the same number creates them.

A way of writing a fraction with a denominator of 100, so 45% means 45 out of every 100, or 0.45 as a decimal.

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

A comparison of two quantities measured in different units, such as kilometres per hour or dollars per kilogram, usually stated as an amount per single unit.

The agreed sequence for calculating an expression: work through brackets, then powers, then multiplication and division, then addition and subtraction, going left to right within each step.

A small raised number showing how many times a base is multiplied by itself; in 2⁴ the index 4 means 2 × 2 × 2 × 2.

A number less than zero, written with a minus sign, used for temperatures below zero, debts, and positions to the left of or below a starting point.

An equation in which the unknown appears only to the first power, such as 3x + 5 = 20; it has a single value as its solution and graphs as a straight line.

Replacing a number with a nearby simpler value by checking the next digit: if it is 5 or more round up, and if it is 4 or less leave the digit unchanged.

The total distance around the outside of a flat shape, found by adding the lengths of all its sides and measured in units such as centimetres or metres.

The amount of flat surface a shape covers, measured in square units such as square centimetres; a rectangle's area is its length multiplied by its width.

The amount of space a solid object occupies, measured in cubic units such as cubic metres; a rectangular prism's volume is length × width × height.

Changing a measurement from one unit to another without altering the actual amount, for example writing 1.5 metres as 150 centimetres by multiplying by 100.

A word part placed before a base unit to show its size, such as kilo (×1000), centi (÷100) and milli (÷1000) in kilometres, centimetres and millilitres.

The amount of turning between two straight lines that meet at a point, measured in degrees, where one full turn is 360 degrees.

The three interior angles of any triangle always add to 180 degrees, which lets you find a missing angle when the other two are known.

In a right-angled triangle the square of the longest side equals the sum of the squares of the other two sides, written as a² + b² = c².

Shapes that have the same shape but not necessarily the same size: matching angles are equal and corresponding sides are all in the same ratio.

A diagram in which every length has been reduced or enlarged by the same factor, such as a map with a scale of 1 centimetre to 5 kilometres.

A way of writing time using four digits from 0000 to 2359, where hours after midday continue past 12, so 3:30 pm becomes 1530.

The average found by adding every value in a data set and dividing the total by how many values there are.

The middle value of a data set once the values are arranged in order; with an even number of values it is the mean of the two middle ones.

The value that occurs most often in a data set; a set may have one mode, several modes, or no mode at all.

A simple measure of spread found by subtracting the smallest value in a data set from the largest value.

A data value lying far away from the rest of the values, often caused by a recording error or an unusual case, which can distort averages.

A table that lists each value or category alongside a count of how many times it occurs, making large data sets easier to summarise and compare.

A graph for numerical data grouped into equal intervals, drawn with bars that touch, where the height of each bar shows the frequency in that interval.

A circular graph divided into sectors whose angles are proportional to each category's share of the total; all sectors together make a full turn.

A graph that plots one numerical variable against another as individual points, used to see whether the two variables appear to be related.

A number from 0 to 1 describing how likely an event is, where 0 means impossible and 1 means certain, often written as a fraction or percentage.

The complete set of all possible outcomes of a chance experiment, such as heads and tails for a single coin toss.

Two events that together cover every possible outcome and cannot both happen, so their probabilities always add to 1.

A group selected from a population so that every member has an equal chance of being chosen, which helps the results represent the whole group.

A flaw in how data are collected or how a sample is chosen that makes the results systematically unrepresentative of the population being studied.