The basic Number Properties (or laws) that apply to arithmetic operations are Commutative Property,
Associative Property, Identity Property and Distributive Property. In this lesson, we will learn the
associative property and identity property of numbers.
The associative property states that the sum or product of a set of numbers is the same, no matter how the numbers are grouped.
An operation is associative if a change in grouping does not change the results. This means the parenthesis (or brackets) can be moved.
Numbers that are added can be grouped in any order.
|For example:||(4 + 5) + 6 = 5 + (4 + 6)|
|(x + y) + z = x + (y + z)|
Numbers that are multiplied can be grouped in any order.
|For example:||(4 × 5) × 6 = 5 × (4 × 6)|
|(x × y) × z = x × (y × z)|
Numbers that are subtracted are NOT associative.
|For example:||(4 – 5) – 6 ≠ 5 – (4 – 6)|
|(x – y) – z ≠ x – (y – z)|
Numbers that are divided are NOT associative.
|For example:||(4 ÷ 5) ÷ 6 ≠ 5 ÷ (4 ÷ 6)|
|(x ÷ y ) ÷ z ≠ y ÷ ( x ÷ z)|
The following table summarizes which number properties are applicable to the different operations:
The following video shows an example on the Associative Property of Addition.
The following video shows an example of the Associative Property of Multiplication.
When you add 0 to any a number, the sum is that number.
For example: 325 + 0 = 325.
When you multiply any number by 1, the product is that number.
For example: 65, 148 × 1 = 65, 148
The product of any number and 0 is 0
For example: 874 × 0 = 0
Identity Property of Addition & Multiplication
The following video shows the commutative & identity properties of addition & multiplication.
What is the identity property? How can you recognize it and name it when you see it? Why does is have the name it has? Why do mathematicians give EVERYTHING, even something as seemingly simple as this a name?
This video shows the zero property.