Simple Arithmetic Operations • 2026 Edition
Addition: a + b = c (combining quantities)
Subtraction: a - b = c (finding difference)
Multiplication: a × b = c (repeated addition)
Division: a ÷ b = c (equal sharing)
Where:
Order of Operations: PEMDAS/BODMAS
• Parentheses/Brackets
• Exponents/Orders
• Multiplication/Division (left to right)
• Addition/Subtraction (left to right)
Addition (+): Combines two numbers
Subtraction (-): Finds the difference
Multiplication (×): Repeated addition
Division (÷): Equal sharing
PEMDAS: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction
| Operation | Symbol | Function | Example |
|---|---|---|---|
| Addition | + | Combine quantities | 5 + 3 = 8 |
| Subtraction | - | Find difference | 5 - 3 = 2 |
| Multiplication | × | Repeated addition | 5 × 3 = 15 |
| Division | ÷ | Equal sharing | 6 ÷ 2 = 3 |
a + b = b + a
a × b = b × a
(a + b) + c = a + (b + c)
(a × b) × c = a × (b × c)
a × (b + c) = (a × b) + (a × c)
Basic arithmetic operations form the foundation of mathematics. These four fundamental operations - addition, subtraction, multiplication, and division - are essential for solving mathematical problems and everyday calculations.
Four fundamental operations with their mathematical properties:
Where:
Key properties of arithmetic operations:
Four fundamental mathematical operations for combining numbers.
Addition (+), Subtraction (-), Multiplication (×), Division (÷)
Foundation of all mathematical calculations.
Standard sequence for evaluating mathematical expressions.
What is the correct order of operations in the expression: 3 + 5 × 2 - 4 ÷ 2?
The answer is B) Multiplication and division first (left to right), then addition and subtraction (left to right). Following the order of operations (PEMDAS/BODMAS), we calculate: 5 × 2 = 10, then 4 ÷ 2 = 2, then 3 + 10 = 13, then 13 - 2 = 11.
The order of operations is crucial for obtaining correct results in mathematical expressions. The acronym PEMDAS (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction) helps remember the sequence. Multiplication and division have equal precedence and are performed left to right, as do addition and subtraction.
PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction
Order of Operations: Standard sequence for evaluating expressions
Left to Right: When operations have equal precedence
• Multiplication and division first
• Addition and subtraction second
• Equal precedence operations go left to right
• Remember PEMDAS
• Same level operations: left to right
• Use parentheses to override order
• Calculating left to right without order
• Not treating multiplication/division equally
• Forgetting left-to-right rule
Calculate: (15 + 3) × 2 - 24 ÷ 4. Show your work following the order of operations.
Following the order of operations (PEMDAS):
Step 1: Parentheses - (15 + 3) = 18
Expression becomes: 18 × 2 - 24 ÷ 4
Step 2: Multiplication and Division (left to right)
18 × 2 = 36
24 ÷ 4 = 6
Expression becomes: 36 - 6
Step 3: Addition and Subtraction (left to right)
36 - 6 = 30
Therefore, the answer is 30.
This problem demonstrates the step-by-step application of order of operations. First, we evaluate expressions in parentheses, then perform multiplication and division from left to right, and finally complete addition and subtraction from left to right. Each step simplifies the expression until we reach the final answer.
Expression: Mathematical phrase with numbers and operations
Order of Operations: Standard sequence for evaluation
Step-by-Step: Sequential evaluation method
• Evaluate parentheses first
• Multiplication/division before addition/subtraction
• Left to right for equal precedence
• Write each step separately
• Circle operations in order
• Check each step before proceeding
• Not completing parentheses first
• Calculating left to right without order
• Forgetting left-to-right rule
Sarah bought 3 notebooks for $2.50 each and 2 pens for $1.75 each. She paid with a $20 bill. How much change should she receive? Write the mathematical expression and solve.
Step 1: Write the mathematical expression
Change = $20 - (3 × $2.50 + 2 × $1.75)
Step 2: Calculate the cost of notebooks
3 × $2.50 = $7.50
Step 3: Calculate the cost of pens
2 × $1.75 = $3.50
Step 4: Calculate total cost
$7.50 + $3.50 = $11.00
Step 5: Calculate change
$20.00 - $11.00 = $9.00
Therefore, Sarah should receive $9.00 in change.
This problem demonstrates how mathematical operations apply to real-world situations. We translate the word problem into a mathematical expression, then follow the order of operations to solve. The parentheses ensure we calculate the total cost before subtracting from the amount paid.
Word Problem: Mathematical problem stated in narrative form
Mathematical Expression: Numbers and operations representing the problem
Real World Application: Practical use of math concepts
• Translate words into mathematical operations
• Use parentheses for grouping
• Follow order of operations
• Identify keywords for operations
• Set up expression first
• Solve step by step
• Not setting up correct expression
• Forgetting order of operations
• Calculation errors
Which property of arithmetic is demonstrated by the equation: 4 × (3 + 7) = (4 × 3) + (4 × 7)? Explain the property and provide another example.
Step 1: Identify the property
This equation demonstrates the Distributive Property of Multiplication over Addition.
Step 2: Explain the property
The Distributive Property states that multiplying a number by a sum is the same as multiplying the number by each addend and then adding the products: a × (b + c) = (a × b) + (a × c)
Step 3: Verify the equation
Left side: 4 × (3 + 7) = 4 × 10 = 40
Right side: (4 × 3) + (4 × 7) = 12 + 28 = 40
Step 4: Provide another example
3 × (5 + 2) = (3 × 5) + (3 × 2)
3 × 7 = 15 + 6
21 = 21 ✓
The distributive property is fundamental in algebra and arithmetic. It allows us to simplify expressions and is essential for factoring. This property connects multiplication with addition, showing how these operations interact. Understanding properties helps in mental math and algebraic manipulations.
Distributive Property: Multiplication over addition/subtraction
Arithmetic Property: Fundamental rule of operations
Algebraic Manipulation: Rearranging mathematical expressions
• a × (b + c) = (a × b) + (a × c)
• Connects multiplication and addition
• Essential for algebra
• Remember: distribute to each term
• Useful for mental math
• Critical for factoring
• Forgetting to distribute to all terms
• Confusing with other properties
• Misapplying to addition over multiplication
Which of the following equations demonstrates the Commutative Property?
The answer is B) 5 + 3 = 3 + 5. The Commutative Property states that the order of operands does not affect the result: a + b = b + a and a × b = b × a. Option A shows the Associative Property, option C shows the Distributive Property, and option D shows that subtraction is not commutative.
The Commutative Property allows us to change the order of numbers in addition and multiplication without changing the result. This property is helpful for mental math and rearranging equations. Note that subtraction and division are not commutative operations, unlike addition and multiplication.
Commutative Property: Order of operands doesn't matter
Addition: a + b = b + a
Multiplication: a × b = b × a
• Addition is commutative
• Multiplication is commutative
• Subtraction is not commutative
• Commutative = order doesn't matter
• Works for + and ×
• Doesn't work for - and ÷
• Thinking subtraction is commutative
• Confusing with associative property
• Not understanding which operations commute
Q: Why is division by zero undefined?
A: Division by zero is undefined because it leads to contradictions:
If 6 ÷ 0 = x, then x × 0 should equal 6
But any number multiplied by 0 equals 0, not 6
Therefore, no value of x satisfies the equation, making division by zero undefined.
Additionally, as the divisor approaches zero, the quotient approaches infinity, which is not a real number.
Q: How can I help my child understand order of operations?
A: Teaching order of operations effectively:
Mnemonics: Use PEMDAS (Please Excuse My Dear Aunt Sally)
Practice: Start with simple expressions and gradually increase complexity
Visual aids: Circle operations in the order they should be performed
Real examples: Use practical problems to show why order matters
Step-by-step: Encourage writing each step separately to avoid confusion
Consistent practice with immediate feedback helps solidify understanding.