Arithmetic operators in MATLAB - Mini Project: Build & Apply

Arithmetic Operators in MATLAB

📖 Scenario: You are helping a small shop owner calculate the total cost of items bought by customers. You will use arithmetic operators to add, subtract, multiply, and divide prices and quantities.

🎯 Goal: Build a simple MATLAB script that uses arithmetic operators to calculate the total price, discount, and final amount to pay.

📋 What You'll Learn

Create variables with exact names and values for prices and quantities

Use arithmetic operators: addition (+), subtraction (-), multiplication (*), and division (/)

Calculate total cost before discount

Calculate discount amount using a discount rate

Calculate final amount after discount

Print the final amount

💡 Why This Matters

🌍 Real World

Calculating prices and discounts is common in shops and online stores to help customers know how much to pay.

💼 Career

Understanding arithmetic operations and variables is essential for programming tasks in data analysis, finance, and software development.

1

Create item prices and quantities

Create variables called priceApple with value 3, priceBanana with value 2, qtyApple with value 5, and qtyBanana with value 7.

MATLAB

% Your code here to create price and quantity variables

Hint

Use the assignment operator = to set values to variables.

2

Set discount rate

Create a variable called discountRate and set it to 0.1 (which means 10%).

MATLAB

priceApple = 3;
priceBanana = 2;
qtyApple = 5;
qtyBanana = 7;
% Your code here to create discountRate variable

Hint

Discount rate is a decimal number representing percentage.

3

Calculate total cost and discount

Calculate the total cost before discount in a variable called totalCost by multiplying prices and quantities and adding them. Then calculate the discount amount in a variable called discountAmount by multiplying totalCost by discountRate.

MATLAB

priceApple = 3;
priceBanana = 2;
qtyApple = 5;
qtyBanana = 7;
discountRate = 0.1;
% Your code here to calculate totalCost and discountAmount

Hint

Use * for multiplication and + for addition.

4

Calculate final amount and display

Calculate the final amount to pay in a variable called finalAmount by subtracting discountAmount from totalCost. Then print the finalAmount using disp.

MATLAB

priceApple = 3;
priceBanana = 2;
qtyApple = 5;
qtyBanana = 7;
discountRate = 0.1;
totalCost = priceApple * qtyApple + priceBanana * qtyBanana;
discountAmount = totalCost * discountRate;
% Your code here to calculate finalAmount and display it

Hint

Use - for subtraction and disp to show the result.

Practice

1. Which arithmetic operator in MATLAB is used to multiply two numbers?

easy

A. +

B. -

C. *

D. ^

Solution

1. Step 1: Identify multiplication operator

   In MATLAB, the symbol * is used to multiply two numbers.

2. Step 2: Confirm other operators

   + is addition, - is subtraction, and ^ is power.

3. Final Answer:

   * -> Option C

4. Quick Check:

   Multiplication = * [OK]

Hint: Remember * means multiply in math and MATLAB [OK]

Common Mistakes:

• Confusing * with + or -
• Using ^ for multiplication
• Forgetting * is needed for multiply

2. Which of the following is the correct MATLAB syntax using the power operator to calculate 5 raised to the power 3?

easy

A. 5^3

B. 5**3

C. power(5,3)

D. 5^^3

Solution

1. Step 1: Identify power operator syntax

   In MATLAB, the caret symbol ^ is used for powers, so 5^3 is correct.

2. Step 2: Check other options

   5**3 and 5^^3 are invalid syntax. power(5,3) is a function but not an operator.

3. Final Answer:

   5^3 -> Option A

4. Quick Check:

   Power operator = ^ [OK]

Hint: Use ^ for powers, not ** or ^^ [OK]

Common Mistakes:

• Using ** like other languages
• Typing ^^ by mistake
• Confusing function with operator

3. What is the output of the following MATLAB code?

a = 10; b = 3; c = a / b;

medium

A. 3.3333

B. 3

C. 7

D. 13

Solution

1. Step 1: Understand division operation

   Variable a is 10, b is 3, so c = a / b divides 10 by 3.

2. Step 2: Calculate division result

   10 divided by 3 equals approximately 3.3333 in MATLAB.

3. Final Answer:

   3.3333 -> Option A

4. Quick Check:

   10 / 3 = 3.3333 [OK]

Hint: Division gives decimal result unless integers used carefully [OK]

Common Mistakes:

• Rounding to 3
• Adding instead of dividing
• Confusing division with subtraction

4. Find the error in this MATLAB expression:

result = 4 + * 5;

medium

A. Wrong operator for addition

B. Missing operand before *

C. Extra semicolon

D. No error

Solution

1. Step 1: Analyze the expression syntax

   The expression 4 + * 5 has two operators + and * without a number between them.

2. Step 2: Identify missing operand

   There should be a number between + and *, but it is missing, causing a syntax error.

3. Final Answer:

   Missing operand before * -> Option B

4. Quick Check:

   Operators need numbers between them [OK]

Hint: Operators must have numbers on both sides [OK]

Common Mistakes:

• Leaving out numbers between operators
• Thinking semicolon causes error
• Using wrong operator symbols

5. You want to calculate the expression (2 + 3) ^ 2 - 4 * 5 in MATLAB. Which code correctly computes this?

hard

A. 2 + (3 ^ 2 - 4) * 5

B. 2 + 3 ^ 2 - 4 * 5

C. (2 + 3) ^ (2 - 4) * 5

D. (2 + 3) ^ 2 - 4 * 5

Solution

1. Step 1: Understand operator precedence and parentheses

   The expression (2 + 3) ^ 2 - 4 * 5 means add 2 and 3 first, then square, then subtract 4 times 5.

2. Step 2: Check each option

   (2 + 3) ^ 2 - 4 * 5 matches the original expression exactly. Others change order or grouping, giving different results.

3. Final Answer:

   (2 + 3) ^ 2 - 4 * 5 -> Option D

4. Quick Check:

   Use parentheses to keep order correct [OK]

Hint: Use parentheses to control math order [OK]

Common Mistakes:

• Ignoring parentheses
• Changing operator order
• Misplacing powers or multiplication