An integer is any whole number that can be positive, negative, or zero. Integers do not have fractional or decimal parts and can be represented on the number line. The set of integers includes:
Positive integers: 1,2,3,…1, 2, 3, \dots
Negative integers: −1,−2,−3,…-1, -2, -3, \dots
Zero: 00
The integers are important because they help represent a wide range of real-life scenarios, from calculating debts to temperatures below freezing. Understanding integers and their operations is a fundamental concept in arithmetic and algebra.
Table of Contents
Integers follow specific rules for addition, subtraction, multiplication, and division. Let’s explore these operations in detail.
Adding integers involves combining two numbers, either both positive or both negative, or one of each. Here are some basic rules:
Positive + Positive: The sum of two positive integers is always positive.
Example: 3+4=73 + 4 = 7
Negative + Negative: The sum of two negative integers is always negative.
Example: −3+(−4)=−7-3 + (-4) = -7
Positive + Negative: The sum of a positive and a negative integer depends on the magnitude (absolute value) of the numbers.
Example: 5+(−3)=25 + (-3) = 2 or −5+3=−2-5 + 3 = -2
Zero + any integer: Adding zero to any integer leaves the integer unchanged.
Example: 0+5=50 + 5 = 5 or 0+(−5)=−50 + (-5) = -5
Subtraction of integers can be seen as the addition of a negative integer. Here’s how it works:
Positive – Positive: If the number being subtracted is smaller, the result is positive; if it's larger, the result is negative.
Example: 7−3=47 - 3 = 4, but 3−7=−43 - 7 = -4
Negative – Negative: The rule follows the same principle as positive subtraction.
Example: −5−(−3)=−5+3=−2-5 - (-3) = -5 + 3 = -2
Adding the opposite: To subtract an integer, add its opposite.
Example: 8−(−4)=8+4=128 - (-4) = 8 + 4 = 12
The multiplication of integers follows a few key rules:
Positive × Positive: The result is positive.
Example: 3×4=123 × 4 = 12
Negative × Negative: The result is positive.
Example: (−3)×(−4)=12(-3) × (-4) = 12
Positive × Negative: The result is negative.
Example: 3×(−4)=−123 × (-4) = -12
Division works similarly to multiplication, with a few differences:
Positive ÷ Positive: The result is positive.
Example: 8÷4=28 ÷ 4 = 2
Negative ÷ Negative: The result is positive.
Example: (−8)÷(−4)=2(-8) ÷ (-4) = 2
Positive ÷ Negative: The result is negative.
Example: 8÷(−4)=−28 ÷ (-4) = -2
Negative ÷ Positive: The result is negative.
Example: (−8)÷4=−2(-8) ÷ 4 = -2
Division by zero: Division by zero is undefined.
Integers are used to represent real-world situations, such as:
Banking: If you owe money to the bank, it’s represented by a negative integer (e.g., -$50). If you have money in your account, it’s a positive integer.
Temperature: Temperatures below zero (like in winter) are represented by negative integers, while positive integers represent temperatures above zero.
Sports Scores: A player’s score may be positive or negative depending on the situation (e.g., points gained or lost).
Integers follow certain properties that help simplify mathematical operations:
Closure Property: The sum, difference, and product of two integers will always be an integer.
Commutative Property: The order of addition or multiplication does not affect the result.
a+b=b+aa + b = b + a
a×b=b×aa \times b = b \times a
Associative Property: The grouping of terms does not affect the result.
(a+b)+c=a+(b+c)(a + b) + c = a + (b + c)
(a×b)×c=a×(b×c)(a \times b) \times c = a \times (b \times c)
Distributive Property: Multiplication distributes over addition.
a×(b+c)=a×b+a×ca \times (b + c) = a \times b + a \times c
Let’s look at a few solved examples to understand how to approach integer-based problems.
Question: What is (−7)+4(-7) + 4?
Solution: Since the integers have opposite signs, subtract the smaller absolute value from the larger one and use the sign of the larger number.
(−7)+4=−3(-7) + 4 = -3
Question: What is (−12)×3(-12) × 3?
Solution: Since the signs are opposite, the product will be negative.
(−12)×3=−36(-12) × 3 = -36
Question: What is 8÷(−4)8 ÷ (-4)?
Solution: Dividing a positive number by a negative number results in a negative quotient.
8÷(−4)=−28 ÷ (-4) = -2
(−9)+6=?(-9) + 6 = ?
14−(−7)=?14 - (-7) = ?
(−5)×(−3)=?(-5) × (-3) = ?
(−20)÷4=?(-20) ÷ 4 = ?
Find the sum of (−7)+(−3)+5(-7) + (-3) + 5.
Integers are not only fundamental to mathematics but also play an important role in solving real-life problems:
Financial Calculations: Negative integers are used to represent debts, while positive integers represent assets or earnings.
Temperature Measurement: The temperature scale in many parts of the world uses negative numbers to represent temperatures below freezing.
Height or Depth: In surveying, negative integers may be used to measure depths below sea level.
Integers are a crucial concept in mathematics, and understanding how to manipulate them using the basic operations - addition, subtraction, multiplication, and division - lays the foundation for more advanced topics. Whether you’re working with financial calculations, measuring temperatures, or solving algebraic equations, integers are an essential tool for solving real-world problems.
Answer: Positive integers are greater than zero, while negative integers are less than zero.
Answer: If the signs are different, the product is always negative.
Answer: Division by zero is undefined.
Answer: Yes, when you add two negative integers, the sum will always be negative.
By mastering integer questions, you’ll enhance your mathematical skills and gain confidence in handling a wide variety of problems.Learn more at orchids International.