Grade 6 → Number System → Integers ↓
Properties of Integer Operations
Integers are a set of numbers that includes zero, positive whole numbers, and negative whole numbers. In mathematics, we often perform various operations on integers such as addition, subtraction, multiplication, and division. Understanding the properties of integer operations is important in simplifying expressions and solving equations.
Addition of integers
When we add integers, we follow some simple rules based on the signs of the numbers:
- If both integers are positive, the result will be positive. For example,
3 + 5 = 8
. - If both integers are negative, the result will be negative. For example,
(-3) + (-5) = -8
. - If one integer is positive and the other is negative, subtract the smaller absolute value from the larger absolute value, and give the result the sign of the integer with the larger absolute value. For example,
5 + (-3) = 2
and-5 + 3 = -2
.
Subtraction of integers
Subtraction of integers can be turned into an addition problem. Subtracting an integer is the same as adding its opposite. For example:
7 - 3
can be written as7 + (-3)
which equals4
.-4 - 2
can be written as-4 + (-2)
which equals-6
.-3 - (-5)
can be written as-3 + 5
which equals2
.
Multiplication of integers
Consider the following rules when multiplying integers:
- The product of two integers with the same sign is positive. For example,
2 × 3 = 6
and(-2) × (-3) = 6
. - The product of two integers with different signs is negative. For example,
2 × (-3) = -6
and(-2) × 3 = -6
. - The product of any integer and zero is zero. For example,
7 × 0 = 0
.
Division of integers
Division of integers follows the same rules as for multiplication:
- The quotient of two integers with the same sign is positive. For example,
8 ÷ 2 = 4
and(-8) ÷ (-2) = 4
. - The quotient of two integers with different signs is negative. For example,
8 ÷ (-2) = -4
and(-8) ÷ 2 = -4
. - Division by zero is undefined. We cannot divide any number by zero.
Properties of integer operations
In addition to these basic rules, there are also some properties that integer operations obey:
1. Exchangeable assets
The commutative property states that changing the order of numbers in an operation does not change the result.
- Addition:
a + b = b + a
. For example,3 + 5 = 5 + 3 = 8
. - Multiplication:
a × b = b × a
. For example,4 × 6 = 6 × 4 = 24
.
2. Associative property
The associative property states that the way numbers are grouped in an operation has no effect on the result.
- Addition:
(a + b) + c = a + (b + c)
. For example,(1 + 2) + 3 = 1 + (2 + 3) = 6
. - Multiplication:
(a × b) × c = a × (b × c)
For example,(2 × 3) × 4 = 2 × (3 × 4) = 24
.
3. Distributive property
The distributive property connects the operations of multiplication and addition. It states that multiplying a sum by a number gives the same result as multiplying each sum by that number and then adding the products.
a × (b + c) = a × b + a × c
For example, 2 × (3 + 4) = 2 × 3 + 2 × 4 = 6 + 8 = 14
.
4. Identity property
The identity property states that there are certain numbers which when used in operations with any number do not change the value of that number.
- Additive identity: The number
0
is the additive identity becausea + 0 = a
. - Multiplication Identity: The number
1
is a multiplication identity becausea × 1 = a
.
5. Inverse property
The inverse property states that every number has an opposite, and when they are added together, they provide the identity element.
- Additive Inverse: The additive inverse of any number
a
is-a
, sincea + (-a) = 0
. - Multiplicative Inverse: The multiplicative inverse of a number is
1/a
, which is mainly found in rational numbers.
6. Zero property of multiplication
The zero property states that multiplying any number by 0
will give the result 0
.
a × 0 = 0
For example, 7 × 0 = 0
Conclusion
Understanding the properties of integer operations helps us simplify and solve mathematical problems more efficiently. The commutative, associative, distributive, identity, inverse, and zero properties each have unique characteristics that apply to the addition and multiplication of integers, making them fundamental concepts in mathematics.