1.2 Natural Numbers
Prime Number
Anumber which can be divided evenly only by 1, or itself. It must be a whole number greater than 1.
Even Number
Any integer (not a fraction) that can be divided exactly by 2. The last digit is 0, 2, 4, 6 or 8
Odd Number
Any integer (not a fraction) that cannot be divided exactly by 2. The last digit is 1, 3, 5, 7 or 9
Ascending
Becoming bigger
Descending
Becoming smaller
Estimating
Finding a value that is close enough to the right answer, usually with some thought or calculation involved.
Place Value
In the number 555, each 5 in a different place has a different value.
Rounding
Making a number simpler but keeping its value close to what it was. It is the best known estimation method.
Consecutive Numbers
Numbers which differ by one e.g., 5, 6, and 7
Factor
Numbers you can multiply together to get another number
Lowest Common Multiple (LCM)
The LCM of two or more numbers is the smallest number that these numbers will divide into exactly. Example: the LCM of 3 and 5 is 15, because 15 is a multiple of 3 and also a multiple of 5.
Square Root
The _________________ of a number is a value that, when multiplied by itself, gives the number. Example: 4 × 4 = 16, so √16 is 4. The symbol is √
Quotient
The answer after you divide one number by another
Product
The answer when two or more numbers are multiplied together.
Highest Common Factor (HCF)
The highest number that divides exactly into two or more numbers. Abbreviated "HCF". Example: the HCF of 12 and 16 is 4, because 1, 2 and 4 are common factors of both 12 and 16, and 4 is the greatest.
Square Number
The number we get after multiplying an integer (not a fraction) by itself.
Divisor
The number you divide by dividend ÷ divisor = quotient Example: in 12 ÷ 3 = 4, 3 is the ______________
Subtraction
The operation or process of finding the difference between two numbers or quantities, represented by a minus sign (−). Taking one number away from another. It is the opposite or inverse of addition.
Inverse Operation
The operation that reverses the effect of another operation. Addition and subtraction are examples of this. Multiplication and division are also examples of this.
Indices
The plural of index
Sum
The result of adding two or more numbers.
Multiple
The result of multiplying a number by an integer (not by a fraction). Examples: • 12 is a ______________ of 3, as 3 × 4 = 12
Difference
The result of subtracting one number from another. How much one number differs from another.
Order of Operations (BIMDAS)
The rules that say which calculation or operation comes first in an expression: - Brackets - Indices - Multiplication - Division - Addition - Subtraction
Numeral
The symbols we use to denote numbers.
Natural Numbers
They are represented by the set N={1, 2, 3, 4, 5, 6, 7,...} This is an infinite set.
Multiplication
This is repeated addition of numbers or getting the product of those numbers. It is the opposite or inverse of division.
Division
This is splitting into equal parts or groups. It is the result of "fair sharing". It is the opposite or inverse of multiplication We use the ÷ symbol, or sometimes the / symbol. 12 / 3 = 4 12 ÷ 3 = 4
Index
This says how many times to multiply the number by itself. It is written as a small number to the right and above the base number. It is also known as a power or exponent.
Array Method
Using rows and columns to help with multiplication.
Base Ten
We count in tens, probably because most people have ten 'digits' on their hands.
Prime Factor
A factor that is a prime number: one of the prime numbers that, when multiplied, give the original number.
Twin Primes
A pair of primes that differ by 2. For example, 3 and 5 or 17 and 19.
Number Line
A way of helping us to put numbers in order. Numbers get bigger from left to right. Numbers get smaller from right to left.
Composite Number
A whole number that can be divided evenly by numbers other than 1 or itself.
Operation
An action or procedure which produces a new value from input values.
Addition
An example of an operation. It is often represented by + symbol. It is finding the total, or sum, by combining two or more numbers. It is the opposite or inverse of subtraction.
