BIDMAS: IB Exams Comprehensive Notes
Welcome to our detailed guide on **BIDMAS** for IB Exams. Whether you're a student preparing for the International Baccalaureate (IB) Mathematics exams or seeking to strengthen your foundational skills in handling the order of operations in mathematical expressions, this guide offers thorough explanations, a tree diagram illustrating BIDMAS, properties, methods, IB-style exam questions with answers, strategies, common mistakes, practice questions, combined exercises, and additional resources to help you excel in the BIDMAS section of your IB Mathematics assessments.
Introduction
**BIDMAS** stands for Brackets, Indices, Division and Multiplication, Addition and Subtraction. It is an acronym that represents the order of operations used to solve mathematical expressions. Understanding and correctly applying BIDMAS is crucial for solving equations accurately and efficiently in IB Mathematics.
Importance of BIDMAS in IB Problem Solving
Understanding and effectively applying BIDMAS is fundamental in IB Mathematics for several reasons:
- Accuracy: Ensures that mathematical expressions are interpreted and solved correctly.
- Efficiency: Helps in simplifying complex expressions quickly.
- Foundation for Advanced Topics: Critical for higher-level mathematics, including algebra, calculus, and beyond.
- Consistency: Provides a standardized approach to solving mathematical problems.
Mastery of BIDMAS enhances problem-solving skills, reduces errors, and improves overall mathematical proficiency, which is essential for success in IB exams.
Basic Concepts of BIDMAS
BIDMAS outlines the sequence in which operations should be performed to correctly solve mathematical expressions.
Understanding the Components of BIDMAS
- Brackets (B): Solve expressions inside brackets first. This includes parentheses (), square brackets [], and curly braces {}.
- Indices (I): Calculate exponents or powers next.
- Division (D) and Multiplication (M): Perform these operations from left to right.
- Addition (A) and Subtraction (S): Finally, perform addition and subtraction from left to right.
Tree Diagram of BIDMAS
A tree diagram can help visualize the hierarchy of operations in BIDMAS. Below is a tree diagram illustrating the order of operations:
-
Brackets
-
Indices
-
Division & Multiplication
-
Addition & Subtraction
-
-
-
This hierarchical structure ensures that each operation is performed in the correct sequence to arrive at the accurate solution.
Properties of BIDMAS
Understanding the properties that govern BIDMAS is essential for manipulating and simplifying mathematical expressions effectively.
1. Associativity
- Addition and Multiplication: These operations are associative, meaning the grouping of numbers does not affect the result.
- Example: \( (2 + 3) + 4 = 2 + (3 + 4) \)
2. Commutativity
- Addition and Multiplication: These operations are commutative, meaning the order of numbers does not affect the result.
- Example: \( 3 + 5 = 5 + 3 \)
3. Distributive Property
- Multiplication over Addition/Subtraction: Allows the multiplication of a single term by each term inside a bracket.
- Example: \( a(b + c) = ab + ac \)
Methods in Applying BIDMAS
Various systematic methods are employed to handle BIDMAS effectively in different mathematical contexts.
1. Step-by-Step Approach
Break down complex expressions into smaller, manageable parts by following the BIDMAS order.
Example: Simplify \( 2 + 3 \times (4^2 - 6) \)
Solution:
- Brackets: \( 4^2 - 6 = 16 - 6 = 10 \)
- Indices: Already handled within brackets.
- Multiplication: \( 3 \times 10 = 30 \)
- Addition: \( 2 + 30 = 32 \)
Therefore, \( 2 + 3 \times (4^2 - 6) = 32 \).
2. Using Parentheses Effectively
Employ parentheses to clearly indicate the order of operations, especially in complex expressions.
Example: Simplify \( 5 + 6 \times 2^3 \)
Solution:
- Indices: \( 2^3 = 8 \)
- Multiplication: \( 6 \times 8 = 48 \)
- Addition: \( 5 + 48 = 53 \)
Therefore, \( 5 + 6 \times 2^3 = 53 \).
3. Rearranging Terms for Clarity
Rearrange terms to group like operations together, making it easier to follow the BIDMAS order.
Example: Simplify \( 7 + 3 \times (2 + 5) - 4 \)
Solution:
- Brackets: \( 2 + 5 = 7 \)
- Multiplication: \( 3 \times 7 = 21 \)
- Addition and Subtraction: \( 7 + 21 - 4 = 24 \)
Therefore, \( 7 + 3 \times (2 + 5) - 4 = 24 \).
Calculations with BIDMAS
Performing calculations accurately involves applying BIDMAS rules correctly across different operations.
1. Simplifying Expressions
Example: Simplify \( 4 + 2 \times (3^2 - 1) \)
Solution:
Brackets: \( 3^2 - 1 = 9 - 1 = 8 \)
Multiplication: \( 2 \times 8 = 16 \)
Addition: \( 4 + 16 = 20 \)
Therefore, \( 4 + 2 \times (3^2 - 1) = 20 \).
2. Solving Equations with BIDMAS
Example: Solve for x: \( 2x + 3(4 - x) = 14 \)
Solution:
- Brackets: \( 4 - x \)
- Distribute: \( 3 \times (4 - x) = 12 - 3x \)
- Combine like terms: \( 2x + 12 - 3x = 14 \) → \( -x + 12 = 14 \)
- Subtract 12 from both sides: \( -x = 2 \)
- Multiply both sides by -1: \( x = -2 \)
Therefore, \( x = -2 \).
3. Evaluating Expressions with Multiple Operations
Example: Evaluate \( 5 + 6 \times (2^3) - 4 \)
Solution:
Indices: \( 2^3 = 8 \)
Multiplication: \( 6 \times 8 = 48 \)
Addition and Subtraction: \( 5 + 48 - 4 = 49 \)
Therefore, \( 5 + 6 \times (2^3) - 4 = 49 \).
Examples of Problem Solving with BIDMAS
Understanding through examples is key to mastering the BIDMAS topic. Below are a variety of IB-style problems ranging from easy to hard, each with detailed solutions.
Example 1: Basic Simplification
Problem: Simplify \( 3 + 4 \times 2 \)
Solution:
According to BIDMAS, perform multiplication before addition.
Multiplication: \( 4 \times 2 = 8 \)
Addition: \( 3 + 8 = 11 \)
Therefore, \( 3 + 4 \times 2 = 11 \).
Example 2: Using Brackets
Problem: Simplify \( (5 + 3) \times 2 \)
Solution:
Brackets first: \( 5 + 3 = 8 \)
Then multiplication: \( 8 \times 2 = 16 \)
Therefore, \( (5 + 3) \times 2 = 16 \).
Example 3: Multiple Operations
Problem: Simplify \( 7 + 3 \times (10 - 2)^2 \)
Solution:
Brackets: \( 10 - 2 = 8 \)
Indices: \( 8^2 = 64 \)
Multiplication: \( 3 \times 64 = 192 \)
Addition: \( 7 + 192 = 199 \)
Therefore, \( 7 + 3 \times (10 - 2)^2 = 199 \).
Example 4: Negative Numbers
Problem: Simplify \( -2 + 5 \times (-3) \)
Solution:
Multiplication: \( 5 \times (-3) = -15 \)
Addition: \( -2 + (-15) = -17 \)
Therefore, \( -2 + 5 \times (-3) = -17 \).
Example 5: Complex Expression
Problem: Simplify \( 4 \times (6 + 2^3) - 5 \)
Solution:
Indices: \( 2^3 = 8 \)
Brackets: \( 6 + 8 = 14 \)
Multiplication: \( 4 \times 14 = 56 \)
Subtraction: \( 56 - 5 = 51 \)
Therefore, \( 4 \times (6 + 2^3) - 5 = 51 \).
Word Problems: Application of BIDMAS in IB Exams
Applying BIDMAS concepts to real-life scenarios enhances understanding and demonstrates their practical utility. Here are several IB-style word problems that incorporate these concepts, along with their solutions.
Example 1: Financial Calculation
Problem: A store sells 5 packs of pens at $3 each and 4 notebooks at $2 each. Calculate the total cost.
Solution:
Calculate the cost for pens: \( 5 \times 3 = 15 \)
Calculate the cost for notebooks: \( 4 \times 2 = 8 \)
Total cost: \( 15 + 8 = 23 \)
Therefore, the total cost is **$23**.
Example 2: Physics Calculation
Problem: The force applied on an object is calculated by \( F = m \times a \), where mass \( m = 2 \times 10^3 \) kg and acceleration \( a = 3 \times 10^2 \) m/s². Calculate the force.
Solution:
Apply BIDMAS for multiplication:
\( F = (2 \times 10^3) \times (3 \times 10^2) = 6 \times 10^5 \) N
Therefore, the force applied is \( 6 \times 10^5 \) Newtons.
Example 3: Engineering Calculation
Problem: An engineer designs a component that requires \( 4 \times (5 + 3)^2 - 10 \) units of material. Calculate the amount of material needed.
Solution:
Brackets: \( 5 + 3 = 8 \)
Indices: \( 8^2 = 64 \)
Multiplication: \( 4 \times 64 = 256 \)
Subtraction: \( 256 - 10 = 246 \)
Therefore, the component requires **246** units of material.
Example 4: Chemistry Reaction
Problem: In a chemical reaction, \( 2 \times (3 + 4)^2 - 5 \) grams of reactant are needed. Calculate the amount required.
Solution:
Brackets: \( 3 + 4 = 7 \)
Indices: \( 7^2 = 49 \)
Multiplication: \( 2 \times 49 = 98 \)
Subtraction: \( 98 - 5 = 93 \) grams
Therefore, **93 grams** of reactant are needed.
Example 5: Economics Calculation
Problem: A company's profit is calculated by \( P = R - C \), where \( R = 5 \times (200 + 3^2) \) and \( C = 4 \times 10^2 \). Calculate the profit.
Solution:
Calculate Revenue (R):
\( 200 + 3^2 = 200 + 9 = 209 \)
\( R = 5 \times 209 = 1045 \)
Calculate Cost (C):
\( C = 4 \times 10^2 = 400 \)
Calculate Profit (P):
\( P = 1045 - 400 = 645 \)
Therefore, the company's profit is **$645**.
Strategies and Tips for Applying BIDMAS in IB Exams
Enhancing your skills in BIDMAS involves employing effective strategies and consistent practice. Here are some tips to help you improve:
1. Memorize the BIDMAS Order
Ensure that you have the BIDMAS acronym and its corresponding operations firmly memorized. This foundational knowledge is crucial for accurate problem-solving.
Mnemonic: Remember the acronym BIDMAS (Brackets, Indices, Division and Multiplication, Addition and Subtraction) to recall the order.
2. Practice Simplifying Expressions
Regularly practice simplifying various mathematical expressions using BIDMAS. Start with simple problems and gradually move to more complex ones.
Example: Simplify \( 6 + 2 \times (3^2) - 4 \)
3. Use Parentheses Strategically
Use parentheses to group operations clearly, especially in complex expressions. This helps in visualizing the order in which operations should be performed.
Example: \( 5 + (3 \times 2) \)
4. Break Down Complex Problems
For expressions with multiple operations, break them down into smaller parts. Solve each part step-by-step following BIDMAS.
Example: Simplify \( 4 \times (2 + 3) - (5^2) \)
5. Double-Check Your Work
After simplifying an expression, review each step to ensure that BIDMAS rules were correctly applied. This helps in identifying and correcting any mistakes.
Example: After simplifying, reverse the steps to confirm accuracy.
6. Utilize Visual Aids
Use visual aids like tree diagrams and step-by-step breakdowns to understand the hierarchy of operations. This reinforces the BIDMAS order and aids in memory retention.
7. Time Management
During exams, manage your time efficiently by quickly identifying the order of operations in each problem. Practice timed exercises to improve speed and accuracy.
8. Practice with Real-World Scenarios
Apply BIDMAS to real-world problems to see its practical applications. This enhances understanding and makes abstract concepts more concrete.
Example: Calculating total cost with multiple operations, such as discounts and taxes.
Common Mistakes in Applying BIDMAS and How to Avoid Them
Being aware of common errors can help you avoid them and improve your calculation accuracy.
1. Ignoring the Order of Operations
Mistake: Performing operations out of the BIDMAS order, leading to incorrect results.
Solution: Always follow the BIDMAS hierarchy strictly. Start with brackets, then indices, followed by division/multiplication, and finally addition/subtraction.
Example:
Incorrect: \( 2 + 3 \times 4 = 20 \)
Correct: \( 2 + (3 \times 4) = 14 \)
2. Misplacing Brackets
Mistake: Incorrectly placing brackets or misinterpreting their scope.
Solution: Ensure brackets encompass only the intended operations. Use different types of brackets ((), [], {}) as needed for clarity.
Example:
Incorrect: \( 5 + (3 \times 2 \) – Missing closing bracket
Correct: \( 5 + (3 \times 2) \)
3. Incorrectly Applying Indices
Mistake: Miscalculating exponents or forgetting to apply them within brackets.
Solution: Double-check calculations involving exponents and ensure they are applied before proceeding to other operations.
Example:
Incorrect: \( (2 + 3)^2 = 25 \)
Correct: \( (2 + 3)^2 = 5^2 = 25 \)
4. Overlooking Negative Signs in Operations
Mistake: Ignoring or misapplying negative signs, especially in subtraction and multiplication.
Solution: Pay close attention to negative signs. Remember that subtracting a positive is equivalent to adding a negative, and vice versa.
Example:
Incorrect: \( 5 - 3 \times 2 = 4 \)
Correct: \( 5 - (3 \times 2) = 5 - 6 = -1 \)
5. Misapplying Division and Multiplication
Mistake: Performing division before multiplication or vice versa when they appear sequentially.
Solution: Since division and multiplication are of equal priority, perform them from left to right as they appear in the expression.
Example:
Incorrect: \( 8 \div 4 \times 2 = 4 \)
Correct: \( (8 \div 4) \times 2 = 2 \times 2 = 4 \)
6. Adding or Subtracting Before Multiplying or Dividing
Mistake: Performing addition or subtraction before multiplication or division without respecting BIDMAS.
Solution: Always perform multiplication or division before addition or subtraction unless brackets indicate otherwise.
Example:
Incorrect: \( 3 + 4 \times 2 = 14 \)
Correct: \( 3 + (4 \times 2) = 11 \)
Practice Questions: Test Your BIDMAS Skills
Practicing with a variety of problems is key to mastering BIDMAS. Below are IB-style practice questions categorized by difficulty level, along with their solutions.
Level 1: Easy
- Simplify \( 2 + 3 \times 4 \).
- Calculate \( (5 + 3) \times 2 \).
- Simplify \( 10 - 2^3 \).
- Evaluate \( 6 + 4 \times (2 + 1) \).
- Simplify \( 7 - 3 \times 2 \).
Solutions:
-
Solution:
Perform multiplication first: \( 3 \times 4 = 12 \)
Then add: \( 2 + 12 = 14 \) -
Solution:
Solve brackets: \( 5 + 3 = 8 \)
Then multiply: \( 8 \times 2 = 16 \) -
Solution:
Calculate indices: \( 2^3 = 8 \)
Then subtract: \( 10 - 8 = 2 \) -
Solution:
Solve brackets: \( 2 + 1 = 3 \)
Then multiply: \( 4 \times 3 = 12 \)
Then add: \( 6 + 12 = 18 \) -
Solution:
Perform multiplication first: \( 3 \times 2 = 6 \)
Then subtract: \( 7 - 6 = 1 \)
Level 2: Medium
- Simplify \( 4 \times (3 + 2)^2 \).
- Calculate \( 10 + 5 \times 2^3 - 4 \).
- Simplify \( (6 + 2) \times (5 - 3) \).
- Evaluate \( 8 \times 2 + 3^3 \).
- Simplify \( 9 - 3 \times (2 + 1)^2 \).
Solutions:
-
Solution:
Solve brackets: \( 3 + 2 = 5 \)
Calculate indices: \( 5^2 = 25 \)
Then multiply: \( 4 \times 25 = 100 \) -
Solution:
Calculate indices: \( 2^3 = 8 \)
Multiply: \( 5 \times 8 = 40 \)
Then add and subtract: \( 10 + 40 - 4 = 46 \) -
Solution:
Solve brackets: \( 6 + 2 = 8 \) and \( 5 - 3 = 2 \)
Then multiply: \( 8 \times 2 = 16 \) -
Solution:
Perform multiplication first: \( 8 \times 2 = 16 \)
Calculate indices: \( 3^3 = 27 \)
Then add: \( 16 + 27 = 43 \) -
Solution:
Solve brackets: \( 2 + 1 = 3 \)
Calculate indices: \( 3^2 = 9 \)
Multiply: \( 3 \times 9 = 27 \)
Then subtract: \( 9 - 27 = -18 \)
Level 3: Hard
- Simplify \( 5 + 2 \times (3^2 + 4) \).
- Calculate \( (4 + 2)^3 - 5 \times 3 \).
- Simplify \( 7 \times (2 + 3)^2 - 10 \).
- Evaluate \( 9 - 3 \times (4 - 2)^3 \).
- Simplify \( 6 \times (5 + 2^2) - (3^3 + 1) \).
Solutions:
-
Solution:
Solve brackets: \( 3^2 + 4 = 9 + 4 = 13 \)
Multiply: \( 2 \times 13 = 26 \)
Then add: \( 5 + 26 = 31 \) -
Solution:
Solve brackets: \( 4 + 2 = 6 \)
Calculate indices: \( 6^3 = 216 \)
Multiply: \( 5 \times 3 = 15 \)
Then subtract: \( 216 - 15 = 201 \) -
Solution:
Solve brackets: \( 2 + 3 = 5 \)
Calculate indices: \( 5^2 = 25 \)
Multiply: \( 7 \times 25 = 175 \)
Then subtract: \( 175 - 10 = 165 \) -
Solution:
Solve brackets: \( 4 - 2 = 2 \)
Calculate indices: \( 2^3 = 8 \)
Multiply: \( 3 \times 8 = 24 \)
Then subtract: \( 9 - 24 = -15 \) -
Solution:
Solve brackets: \( 2^2 = 4 \), so \( 5 + 4 = 9 \)
Multiply: \( 6 \times 9 = 54 \)
Calculate indices: \( 3^3 = 27 \)
Add: \( 27 + 1 = 28 \)
Then subtract: \( 54 - 28 = 26 \)
Word Problems: Application of BIDMAS in IB Exams
Applying BIDMAS concepts to real-life scenarios enhances understanding and demonstrates their practical utility. Here are several IB-style word problems that incorporate these concepts, along with their solutions.
Example 1: Construction Calculation
Problem: A construction company calculates the total materials needed using the formula \( M = 2 \times (B + 3)^2 - 5 \), where B is the number of buildings. If there are 4 buildings, calculate the total materials needed.
Solution:
Substitute B = 4 into the formula:
\( M = 2 \times (4 + 3)^2 - 5 \)
Solve brackets: \( 4 + 3 = 7 \)
Calculate indices: \( 7^2 = 49 \)
Multiply: \( 2 \times 49 = 98 \)
Subtract: \( 98 - 5 = 93 \)
Therefore, the total materials needed are **93** units.
Example 2: Financial Investment
Problem: An investment grows according to the formula \( A = P + 4 \times (r^2 + 2) \), where P is the principal amount and r is the rate of interest. If P = $1,000 and r = 3, calculate the amount after growth.
Solution:
Substitute P = 1000 and r = 3 into the formula:
\( A = 1000 + 4 \times (3^2 + 2) \)
Solve indices: \( 3^2 = 9 \)
Add within brackets: \( 9 + 2 = 11 \)
Multiply: \( 4 \times 11 = 44 \)
Add: \( 1000 + 44 = 1044 \)
Therefore, the amount after growth is **$1,044**.
Example 3: Physics Formula
Problem: The kinetic energy (KE) of an object is given by \( KE = \frac{1}{2} \times m \times v^2 \), where m is mass and v is velocity. If an object has a mass of 10 kg and velocity of 5 m/s, calculate its kinetic energy.
Solution:
Substitute m = 10 kg and v = 5 m/s into the formula:
\( KE = \frac{1}{2} \times 10 \times 5^2 \)
Solve indices: \( 5^2 = 25 \)
Multiply: \( \frac{1}{2} \times 10 = 5 \)
Then, \( 5 \times 25 = 125 \) J
Therefore, the kinetic energy is **125 Joules**.
Example 4: Engineering Design
Problem: An engineer designs a component with the stress calculated by \( S = 3 \times (T + 2)^3 - 7 \), where T is the temperature in degrees Celsius. If T = 4°C, calculate the stress.
Solution:
Substitute T = 4 into the formula:
\( S = 3 \times (4 + 2)^3 - 7 \)
Solve brackets: \( 4 + 2 = 6 \)
Calculate indices: \( 6^3 = 216 \)
Multiply: \( 3 \times 216 = 648 \)
Subtract: \( 648 - 7 = 641 \)
Therefore, the stress is **641** units.
Example 5: Chemical Reaction
Problem: The yield of a chemical reaction is given by \( Y = 5 \times (C + 4)^2 - 10 \), where C is the concentration of the reactant in mol/L. If C = 3 mol/L, calculate the yield.
Solution:
Substitute C = 3 into the formula:
\( Y = 5 \times (3 + 4)^2 - 10 \)
Solve brackets: \( 3 + 4 = 7 \)
Calculate indices: \( 7^2 = 49 \)
Multiply: \( 5 \times 49 = 245 \)
Subtract: \( 245 - 10 = 235 \)
Therefore, the yield is **235** units.
Strategies and Tips for Applying BIDMAS in IB Exams
Enhancing your skills in BIDMAS involves employing effective strategies and consistent practice. Here are some tips to help you improve:
1. Memorize the BIDMAS Order
Ensure that you have the BIDMAS acronym and its corresponding operations firmly memorized. This foundational knowledge is crucial for accurate problem-solving.
Mnemonic: Remember the acronym BIDMAS (Brackets, Indices, Division and Multiplication, Addition and Subtraction) to recall the order.
2. Practice Simplifying Expressions
Regularly practice simplifying various mathematical expressions using BIDMAS. Start with simple problems and gradually move to more complex ones.
Example: Simplify \( 6 + 2 \times (3^2) - 4 \)
3. Use Parentheses Strategically
Employ parentheses to clearly indicate the order of operations, especially in complex expressions. This helps in visualizing the order in which operations should be performed.
Example: \( 5 + (3 \times 2) \)
4. Break Down Complex Problems
For expressions with multiple operations, break them down into smaller parts. Solve each part step-by-step following BIDMAS.
Example: Simplify \( 4 \times (2 + 3) - 5 \)
5. Double-Check Your Work
After simplifying an expression, review each step to ensure that BIDMAS rules were correctly applied. This helps in identifying and correcting any mistakes.
Example: After simplifying, reverse the steps to confirm accuracy.
6. Utilize Visual Aids
Use visual aids like tree diagrams and step-by-step breakdowns to understand the hierarchy of operations. This reinforces the BIDMAS order and aids in memory retention.
7. Time Management
During exams, manage your time efficiently by quickly identifying the order of operations in each problem. Practice timed exercises to improve speed and accuracy.
8. Practice with Real-World Scenarios
Apply BIDMAS to real-life problems to see its practical applications. This enhances understanding and makes abstract concepts more concrete.
Example: Calculating total cost with multiple operations, such as discounts and taxes.
Common Mistakes in Applying BIDMAS and How to Avoid Them
Being aware of common errors can help you avoid them and improve your calculation accuracy.
1. Ignoring the Order of Operations
Mistake: Performing operations out of the BIDMAS order, leading to incorrect results.
Solution: Always follow the BIDMAS hierarchy strictly. Start with brackets, then indices, followed by division/multiplication, and finally addition/subtraction.
Example:
Incorrect: \( 2 + 3 \times 4 = 20 \)
Correct: \( 2 + (3 \times 4) = 14 \)
2. Misplacing Brackets
Mistake: Incorrectly placing brackets or misinterpreting their scope.
Solution: Ensure brackets encompass only the intended operations. Use different types of brackets ((), [], {}) as needed for clarity.
Example:
Incorrect: \( 5 + (3 \times 2 \) – Missing closing bracket
Correct: \( 5 + (3 \times 2) \)
3. Incorrectly Applying Indices
Mistake: Miscalculating exponents or forgetting to apply them within brackets.
Solution: Double-check calculations involving exponents and ensure they are applied before proceeding to other operations.
Example:
Incorrect: \( (2 + 3)^2 = 25 \)
Correct: \( (2 + 3)^2 = 5^2 = 25 \)
4. Overlooking Negative Signs in Operations
Mistake: Ignoring or misapplying negative signs, especially in subtraction and multiplication.
Solution: Pay close attention to negative signs. Remember that subtracting a positive is equivalent to adding a negative, and vice versa.
Example:
Incorrect: \( 5 - 3 \times 2 = 4 \)
Correct: \( 5 - (3 \times 2) = 5 - 6 = -1 \)
5. Misapplying Division and Multiplication
Mistake: Performing division before multiplication or vice versa when they appear sequentially.
Solution: Since division and multiplication are of equal priority, perform them from left to right as they appear in the expression.
Example:
Incorrect: \( 8 \div 4 \times 2 = 4 \)
Correct: \( (8 \div 4) \times 2 = 2 \times 2 = 4 \)
6. Adding or Subtracting Before Multiplying or Dividing
Mistake: Performing addition or subtraction before multiplication or division without respecting BIDMAS.
Solution: Always perform multiplication or division before addition or subtraction unless brackets indicate otherwise.
Example:
Incorrect: \( 3 + 4 \times 2 = 14 \)
Correct: \( 3 + (4 \times 2) = 11 \)
IB Exam Questions: BIDMAS with Answers
Below are additional IB-style exam questions on the BIDMAS topic, complete with detailed answers to aid your preparation.
Question 1: Simplifying Complex Expressions
Problem: Simplify the expression \( 5 + 3 \times (2^3 + 1) \).
Solution:
First, solve the brackets: \( 2^3 + 1 = 8 + 1 = 9 \)
Then, perform the multiplication: \( 3 \times 9 = 27 \)
Finally, add: \( 5 + 27 = 32 \)
Therefore, the simplified expression is **32**.
Question 2: Solving Equations with BIDMAS
Problem: Solve for x: \( 2x + 4 \times (3 - x) = 10 \).
Solution:
First, solve the brackets: \( 3 - x \)
Then, perform the multiplication: \( 4 \times (3 - x) = 12 - 4x \)
Substitute back into the equation: \( 2x + 12 - 4x = 10 \)
Combine like terms: \( -2x + 12 = 10 \)
Subtract 12 from both sides: \( -2x = -2 \)
Divide by -2: \( x = 1 \)
Therefore, \( x = 1 \).
Question 3: Evaluating Expressions with Multiple Operations
Problem: Evaluate \( 7 + 4 \times (5 - 2)^2 \).
Solution:
First, solve the brackets: \( 5 - 2 = 3 \)
Then, calculate the indices: \( 3^2 = 9 \)
Perform the multiplication: \( 4 \times 9 = 36 \)
Finally, add: \( 7 + 36 = 43 \)
Therefore, the evaluated expression is **43**.
Question 4: Applying BIDMAS in Real-World Context
Problem: A factory produces \( 5 + 2 \times (10^2 - 50) \) units of product daily. Calculate the number of units produced.
Solution:
First, solve the brackets: \( 10^2 - 50 = 100 - 50 = 50 \)
Then, perform the multiplication: \( 2 \times 50 = 100 \)
Finally, add: \( 5 + 100 = 105 \)
Therefore, the factory produces **105** units of product daily.
Question 5: Complex Calculation
Problem: Simplify \( 8 \times (3 + 2^2) - 4 \).
Solution:
First, solve the indices: \( 2^2 = 4 \)
Then, solve the brackets: \( 3 + 4 = 7 \)
Perform the multiplication: \( 8 \times 7 = 56 \)
Finally, subtract: \( 56 - 4 = 52 \)
Therefore, the simplified expression is **52**.
Combined Exercises: Examples and Solutions
Many mathematical problems require the use of BIDMAS concepts in conjunction with other operations. Below are additional IB-style examples that incorporate these concepts alongside logical reasoning and application to real-world scenarios.
Example 1: Engineering Design
Problem: An engineer calculates the stress on a beam using the formula \( S = 3 \times (F + 2)^2 - 10 \), where F is the force applied in Newtons. If F = 4 N, calculate the stress.
Solution:
Substitute F = 4 into the formula:
\( S = 3 \times (4 + 2)^2 - 10 \)
Solve brackets: \( 4 + 2 = 6 \)
Calculate indices: \( 6^2 = 36 \)
Multiply: \( 3 \times 36 = 108 \)
Subtract: \( 108 - 10 = 98 \)
Therefore, the stress on the beam is **98** units.
Example 2: Financial Planning
Problem: A company’s profit is calculated using \( P = 2x + 5 \times (y^2 - 3) \), where x is the number of products sold and y is the price per product in dollars. If x = 50 and y = 4, calculate the profit.
Solution:
Substitute x = 50 and y = 4 into the formula:
\( P = 2 \times 50 + 5 \times (4^2 - 3) \)
Solve indices: \( 4^2 = 16 \)
Calculate brackets: \( 16 - 3 = 13 \)
Multiply: \( 5 \times 13 = 65 \)
Multiply: \( 2 \times 50 = 100 \)
Add: \( 100 + 65 = 165 \)
Therefore, the company’s profit is **$165**.
Example 3: Physics Calculation
Problem: The kinetic energy (KE) of an object is given by \( KE = \frac{1}{2}m(v^2) \), where m is mass in kg and v is velocity in m/s. Calculate the kinetic energy of an object with m = 10 kg and v = 5 m/s.
Solution:
Substitute m = 10 kg and v = 5 m/s into the formula:
\( KE = \frac{1}{2} \times 10 \times (5^2) \)
Solve indices: \( 5^2 = 25 \)
Multiply: \( \frac{1}{2} \times 10 = 5 \)
Then, \( 5 \times 25 = 125 \) Joules
Therefore, the kinetic energy is **125 Joules**.
Example 4: Chemical Reaction
Problem: In a chemical reaction, the yield Y is calculated by \( Y = 4 \times (C + 1)^3 - 15 \), where C is the concentration in mol/L. If C = 2 mol/L, calculate the yield.
Solution:
Substitute C = 2 into the formula:
\( Y = 4 \times (2 + 1)^3 - 15 \)
Solve brackets: \( 2 + 1 = 3 \)
Calculate indices: \( 3^3 = 27 \)
Multiply: \( 4 \times 27 = 108 \)
Subtract: \( 108 - 15 = 93 \)
Therefore, the yield is **93** units.
Example 5: Economics Calculation
Problem: The demand D for a product is given by \( D = 6 + 2 \times (P - 1)^2 \), where P is the price in dollars. Calculate the demand when P = 3 dollars.
Solution:
Substitute P = 3 into the formula:
\( D = 6 + 2 \times (3 - 1)^2 \)
Solve brackets: \( 3 - 1 = 2 \)
Calculate indices: \( 2^2 = 4 \)
Multiply: \( 2 \times 4 = 8 \)
Add: \( 6 + 8 = 14 \)
Therefore, the demand is **14** units.
Additional Practice Questions: BIDMAS
Further practice with IB-style questions can help solidify your understanding of the BIDMAS topic. Below are additional practice questions categorized by difficulty level, along with their solutions.
Level 1: Easy
- Simplify \( 1 + 2 \times 3 \).
- Calculate \( (4 + 6) \times 2 \).
- Simplify \( 9 - 3^2 \).
- Evaluate \( 7 + 5 \times (2 + 3) \).
- Simplify \( 10 - 4 \times 2 \).
Solutions:
-
Solution:
Perform multiplication first: \( 2 \times 3 = 6 \)
Then add: \( 1 + 6 = 7 \) -
Solution:
Solve brackets: \( 4 + 6 = 10 \)
Then multiply: \( 10 \times 2 = 20 \) -
Solution:
Calculate indices: \( 3^2 = 9 \)
Then subtract: \( 9 - 9 = 0 \) -
Solution:
Solve brackets: \( 2 + 3 = 5 \)
Then multiply: \( 5 \times 5 = 25 \)
Then add: \( 7 + 25 = 32 \) -
Solution:
Perform multiplication first: \( 4 \times 2 = 8 \)
Then subtract: \( 10 - 8 = 2 \)
Level 2: Medium
- Simplify \( 3 \times (2 + 5)^2 \).
- Calculate \( 12 + 6 \times 2^3 - 5 \).
- Simplify \( (7 + 3) \times (4 - 2) \).
- Evaluate \( 10 \times 2 + 3^3 \).
- Simplify \( 15 - 5 \times (3 + 1)^2 \).
Solutions:
-
Solution:
Solve brackets: \( 2 + 5 = 7 \)
Calculate indices: \( 7^2 = 49 \)
Multiply: \( 3 \times 49 = 147 \) -
Solution:
Calculate indices: \( 2^3 = 8 \)
Multiply: \( 6 \times 8 = 48 \)
Add and subtract: \( 12 + 48 - 5 = 55 \) -
Solution:
Solve brackets: \( 7 + 3 = 10 \) and \( 4 - 2 = 2 \)
Multiply: \( 10 \times 2 = 20 \) -
Solution:
Perform multiplication first: \( 10 \times 2 = 20 \)
Calculate indices: \( 3^3 = 27 \)
Then add: \( 20 + 27 = 47 \) -
Solution:
Solve brackets: \( 3 + 1 = 4 \)
Calculate indices: \( 4^2 = 16 \)
Multiply: \( 5 \times 16 = 80 \)
Subtract: \( 15 - 80 = -65 \)
Level 3: Hard
- Simplify \( 4 + 3 \times (5^2 + 2) \).
- Calculate \( (6 + 4)^3 - 2 \times 5 \).
- Simplify \( 8 \times (3 + 2)^2 - 10 \).
- Evaluate \( 12 - 4 \times (2 + 3)^3 \).
- Simplify \( 10 \times (5 + 2^3) - (4^2 + 3) \).
Solutions:
-
Solution:
Solve brackets: \( 5^2 + 2 = 25 + 2 = 27 \)
Multiply: \( 3 \times 27 = 81 \)
Add: \( 4 + 81 = 85 \) -
Solution:
Solve brackets: \( 6 + 4 = 10 \)
Calculate indices: \( 10^3 = 1000 \)
Multiply: \( 2 \times 5 = 10 \)
Subtract: \( 1000 - 10 = 990 \) -
Solution:
Solve brackets: \( 3 + 2 = 5 \)
Calculate indices: \( 5^2 = 25 \)
Multiply: \( 8 \times 25 = 200 \)
Subtract: \( 200 - 10 = 190 \) -
Solution:
Solve brackets: \( 2 + 3 = 5 \)
Calculate indices: \( 5^3 = 125 \)
Multiply: \( 4 \times 125 = 500 \)
Subtract: \( 12 - 500 = -488 \) -
Solution:
Solve brackets: \( 2^3 = 8 \), so \( 5 + 8 = 13 \)
Multiply: \( 10 \times 13 = 130 \)
Calculate indices: \( 4^2 = 16 \)
Add: \( 16 + 3 = 19 \)
Subtract: \( 130 - 19 = 111 \)
Combined Exercises: Examples and Solutions
Many mathematical problems require the use of BIDMAS concepts in conjunction with other operations. Below are additional IB-style examples that incorporate these concepts alongside logical reasoning and application to real-world scenarios.
Example 1: Engineering Design
Problem: An engineer calculates the load on a beam using the formula \( L = 5 \times (F + 2)^2 - 10 \), where F is the force applied in Newtons. If F = 3 N, calculate the load.
Solution:
Substitute F = 3 into the formula:
\( L = 5 \times (3 + 2)^2 - 10 \)
Solve brackets: \( 3 + 2 = 5 \)
Calculate indices: \( 5^2 = 25 \)
Multiply: \( 5 \times 25 = 125 \)
Subtract: \( 125 - 10 = 115 \)
Therefore, the load on the beam is **115** units.
Example 2: Financial Calculation
Problem: A company's revenue is calculated using the formula \( R = 2x + 3 \times (y^2 - 1) \), where x is the number of products sold and y is the price per product in dollars. If x = 100 and y = 4, calculate the revenue.
Solution:
Substitute x = 100 and y = 4 into the formula:
\( R = 2 \times 100 + 3 \times (4^2 - 1) \)
Solve indices: \( 4^2 = 16 \)
Calculate brackets: \( 16 - 1 = 15 \)
Multiply: \( 3 \times 15 = 45 \)
Multiply: \( 2 \times 100 = 200 \)
Add: \( 200 + 45 = 245 \)
Therefore, the company's revenue is **$245**.
Example 3: Physics Calculation
Problem: The potential energy (PE) of an object is given by \( PE = m \times g \times h \), where m is mass in kg, g is acceleration due to gravity (9.8 m/s²), and h is height in meters. Calculate the potential energy of an object with m = 5 kg and h = 10 m.
Solution:
Substitute m = 5 kg, g = 9.8 m/s², and h = 10 m into the formula:
\( PE = 5 \times 9.8 \times 10 \)
Multiply: \( 5 \times 9.8 = 49 \)
Then, \( 49 \times 10 = 490 \) Joules
Therefore, the potential energy is **490 Joules**.
Example 4: Chemistry Reaction
Problem: In a chemical reaction, the yield Y is calculated by \( Y = 6 \times (C + 3)^2 - 12 \), where C is the concentration in mol/L. If C = 2 mol/L, calculate the yield.
Solution:
Substitute C = 2 into the formula:
\( Y = 6 \times (2 + 3)^2 - 12 \)
Solve brackets: \( 2 + 3 = 5 \)
Calculate indices: \( 5^2 = 25 \)
Multiply: \( 6 \times 25 = 150 \)
Subtract: \( 150 - 12 = 138 \)
Therefore, the yield is **138** units.
Example 5: Economics Calculation
Problem: The demand D for a product is given by \( D = 7 + 4 \times (P - 2)^2 \), where P is the price in dollars. Calculate the demand when P = 5 dollars.
Solution:
Substitute P = 5 into the formula:
\( D = 7 + 4 \times (5 - 2)^2 \)
Solve brackets: \( 5 - 2 = 3 \)
Calculate indices: \( 3^2 = 9 \)
Multiply: \( 4 \times 9 = 36 \)
Add: \( 7 + 36 = 43 \)
Therefore, the demand is **43** units.
Summary
Mastering BIDMAS is essential for success in the Order of Operations section of IB Mathematics exams. By understanding the hierarchy of operations, applying the correct rules for simplifying and solving expressions, and practicing consistently, you can enhance your problem-solving accuracy and efficiency. Remember to:
- Understand the BIDMAS acronym and the order of operations it represents.
- Apply the BIDMAS rules systematically when simplifying and evaluating expressions.
- Use parentheses to clearly indicate the intended order of operations.
- Break down complex expressions into smaller, manageable parts.
- Double-check your work to ensure that all operations have been performed in the correct order.
- Practice with a variety of problems to build confidence and proficiency.
- Avoid common mistakes by being mindful of the BIDMAS hierarchy and checking each step carefully.
- Utilize visual aids like tree diagrams to reinforce the order of operations.
- Apply BIDMAS to real-world scenarios to understand its practical applications.
- Develop strong mental math skills to handle BIDMAS operations efficiently without relying solely on calculators.
With dedication and consistent practice, handling BIDMAS will become an integral part of your mathematical toolkit, enabling you to tackle complex problems with confidence and precision.
Additional Resources
Enhance your learning by exploring the following resources: