NUMBER 1

Product of Prime Factors

Finding which prime numbers multiply together to make the original composite number.

Composite number

A whole number that can be made by multiplying other whole numbers.

Significant figure

The number of digits after the first non-zero digit. For example 3.04 and 4500 are both written to 3 significant figures.

Inequality

An inequality compares two values, showing if one is less than, greater than, or simply not equal to another value.

Rational Number

A Rational Number can be made by dividing an integer by an integer. An integer has no fractional part.

Irrational Number

An Irrational Number is a real number that cannot be written as a simple fraction. The decimal goes on forever without repeating.

Number Line

A horizontal line with labelled numbers. A point is chosen on the line to be the origin. Points to the right are positive, and points to the left are negative.

Real Number

Any number you can think of is a Real Number except for infinity and imaginary numbers. Real numbers can be positive, negative or zero.

Whole Number

Whole numbers are the numbers 0, 1, 2, 3, 4, 5, … (and so on)

Natural Number

Whole numbers from 1 and greater.

Estimation

Finding a value that is close enough to the right answer. Round all numbers to 1 significant figure to show an estimate.

Limit (of Accuracy)

Half a unit each side of the unit of measure.

Standard Form

Another name for “scientific notation”. One digit from 1-9 in front of the decimal point, with a power of 10 in the answer.

Ordinary Form

The “normal” form of the number when it is not in standard form.

Prime number

A whole number greater than 1 that has exactly two factors: 1 and itself.

Lowest Common Multiple (LCM)

The smallest positive number that is a multiple of two or more numbers.

Highest Common Factor (HCF)

The largest number that divides exactly into two or more numbers.

Recurring Decimal

A decimal in which a digit or group of digits repeats forever (e.g. 0.333… or 0.142857 repeating).

Round

To approximate a number to a given place value or number of significant figures.

Decimal places

The number of digits after the decimal point.

Power / Index

A small number written above and to the right of a base that tells how many times to multiply the base by itself.

Integer

A whole number that can be positive, negative or zero (… −2, −1, 0, 1, 2 …).

Base number

The number that is raised to a power.

Square root

A value that, when multiplied by itself, gives the original number (symbol √).

Cube root

A value that, when multiplied by itself three times, gives the original number (symbol ∛).