Arithmetic expansion $(( )) in Bash Scripting - Mini Project: Build & Apply

Using Arithmetic Expansion $(( )) in Bash

📖 Scenario: You are managing a small store's daily sales. You want to calculate the total number of items sold by adding the sales from morning and afternoon shifts.

🎯 Goal: Build a simple Bash script that uses arithmetic expansion $(( )) to add two numbers representing sales and display the total.

📋 What You'll Learn

Create two variables morning_sales and afternoon_sales with exact values

Create a variable total_sales that uses arithmetic expansion $(( )) to add the two sales variables

Print the total sales using echo

💡 Why This Matters

🌍 Real World

Calculating totals, counts, or simple math in shell scripts is common for automating tasks like sales reports or inventory checks.

💼 Career

Knowing arithmetic expansion helps you write scripts that handle numbers easily, a useful skill for system administrators and automation engineers.

1

Set up sales variables

Create two variables called morning_sales and afternoon_sales with values 120 and 80 respectively.

Bash Scripting

# Create variables morning_sales and afternoon_sales with values 120 and 80
# Your code here

Need a hint?

Use variable=value format without spaces around =.

2

Calculate total sales

Create a variable called total_sales that uses arithmetic expansion $(( )) to add morning_sales and afternoon_sales.

Bash Scripting

morning_sales=120
afternoon_sales=80
# Calculate total_sales using $(( )) to add morning_sales and afternoon_sales
# Your code here

Need a hint?

Use total_sales=$((morning_sales + afternoon_sales)) to add the two variables.

3

Display the total sales

Use echo to print the value of total_sales.

Bash Scripting

morning_sales=120
afternoon_sales=80
total_sales=$((morning_sales + afternoon_sales))
# Print total_sales using echo
# Your code here

Need a hint?

Use echo $total_sales to show the result.

4

Run the script and see the result

Run the script to display the total sales number. The output should be 200.

Bash Scripting

morning_sales=120
afternoon_sales=80
total_sales=$((morning_sales + afternoon_sales))
echo $total_sales
# Run the script to see the output

Need a hint?

Run the script in your terminal using bash script.sh or ./script.sh if executable.