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Session 7: Decision Making - Basic Conditionals
🤔 Teaching Computers to Make Choices
Today we give our programs the power to think and decide!
From simple yes/no questions to smart decision-making
✨ Programs that can think and choose! ✨
🎯 Today's Decision-Making Mission
🤔
Master if Statements
Basic decision making
⚖️
Comparison Operators
==, !=, >, <, >=, <=
✅
Boolean Logic
True/false concepts
🎮
Interactive Programs
Programs that respond differently
🚦
Control Flow
Direct program behavior
🏆
Age Classifier
Build smart categorization
🧮 Quick Arithmetic Review!
📏 What does PEMDAS stand for?
Parentheses, Exponents, Multiplication, Division, Addition, Subtraction
🔢 What's 17 % 5?
2 (remainder)
🤖 Which operator gives us the remainder?
% (modulus)
🏠 Mathematical Creations Showcase!
🎉 Let's see your math programming magic!
🧮 Super Calculator: Show us your 5-operator calculator with menu!
🏠 Room Calculator: Demonstrate area and perimeter calculations!
⏰ Time Converter: Display your seconds-to-time converter!
💰 Shopping Calculator: Show tax and change calculations!
🎯 PEMDAS Mastery: Share your complex expression predictions!
🔍 Modulus Explorer: Demonstrate even/odd checking!
🌟 Amazing mathematical programming skills!
🤔 Programs Need to Make Decisions Too!
🚦
🚗 In Real Life
If traffic light is red → STOP
If traffic light is green → GO
📱 In Apps
If password is correct → Login
If password is wrong → Try again
🎮 In Games
If player reaches goal → Win!
If player falls → Game over
💻 In Our Programs
If age >= 13 → "You're a teenager!"
If score > 90 → "Excellent work!"
🚪 Meet the 'if' Statement - Your Decision Maker!
Basic if Statement Structure:
if (condition_is_true) {
printf("The condition was true!\n");
}
The Magic Formula:
if (QUESTION) { ANSWER }
🎯 Key Points:
- Condition goes in parentheses ( )
- Code to execute goes in braces { }
- If condition is false, code inside { } is skipped
- If condition is true, code inside { } runs
⚖️ Meet the Comparison Operators!
==
Equal To
Are they exactly the same?
age == 13
!=
Not Equal
Are they different?
score != 0
>
Greater Than
Is left side bigger?
grade > 90
<
Less Than
Is left side smaller?
temp < 32
>=
Greater/Equal
Bigger or same?
age >= 16
<=
Less/Equal
Smaller or same?
speed <= 55
💻 Your First Decision-Making Program!
#include <stdio.h>
int main() {
int age;
printf("Enter your age: ");
scanf("%d", &age);
if (age >= 13) {
printf("You're a teenager! 🎉\n");
}
if (age >= 18) {
printf("You're an adult! 🎓\n");
}
if (age < 13) {
printf("You're still a kid! 🧒\n");
}
return 0;
}
🎯 Test Different Ages:
- Try age 10 → "You're still a kid!"
- Try age 15 → "You're a teenager!"
- Try age 20 → "You're a teenager!" AND "You're an adult!"
🚨 Common Comparison Mistakes to Avoid!
❌ Single = instead of ==
if (age = 13) // WRONG - This assigns!
Correct: if (age == 13) - This compares!
❌ Missing parentheses
if age > 10 // WRONG - Missing ( )
Correct: if (age > 10)
❌ Wrong comparison direction
if (18 < age) // Confusing order
Better: if (age > 18) - More natural
✅ Pro Tips!
- Always use == for comparison
- Put variable on left, value on right
- Use meaningful variable names
- Test with different values
🧠 Comparison Operators Quiz!
🎯 If age = 15, which condition is TRUE?
A) age == 13
Is 15 equal to 13?
B) age > 10
Is 15 greater than 10?
C) age < 14
Is 15 less than 14?
D) age >= 15
Is 15 greater than or equal to 15?
Multiple answers can be correct!
✅ Understanding True and False
🤖
How Computers Think:
Question: Is 15 > 10?
Computer Brain: 15 is greater than 10
Answer: TRUE ✅
Question: Is 8 == 12?
Computer Brain: 8 is not equal to 12
Answer: FALSE ❌
Question: Is 7 <= 7?
Computer Brain: 7 is equal to 7 (satisfies <=)
Answer: TRUE ✅
🎯 If condition is TRUE → Code runs. If FALSE → Code skips!
🎓 Build a Grade Classifier!
#include <stdio.h>
int main() {
int score;
printf("Enter your test score (0-100): ");
scanf("%d", &score);
printf("Your score: %d\n", score);
if (score >= 90) {
printf("Grade: A - Excellent! 🌟\n");
}
if (score >= 80 && score < 90) {
printf("Grade: B - Good job! 👍\n");
}
if (score >= 70 && score < 80) {
printf("Grade: C - Keep working! 📚\n");
}
if (score < 70) {
printf("Grade: Needs Improvement 💪\n");
}
return 0;
}
🗺️ Choose Your Adventure Challenge!
🎮 Build Your First Decision-Based Game
Let's create a simple adventure with choices!
🗡️ Adventure Story Structure:
1. Set the Scene: You're exploring a mysterious cave...
2. Present Choice: Do you go left or right? (Enter 1 or 2)
3. Use if Statements: Different outcomes for each choice
4. Add Consequences: Each path leads to different results
🚀 Let's code this adventure together!
👶 Age Category Classifier Challenge!
#include <stdio.h>
int main() {
int age;
printf("=== AGE CATEGORY CLASSIFIER ===\n");
printf("Enter someone's age: ");
scanf("%d", &age);
if (age <= 2) {
printf("Category: Baby 👶\n");
}
if (age >= 3 && age <= 12) {
printf("Category: Child 🧒\n");
}
if (age >= 13 && age <= 19) {
printf("Category: Teenager 🎸\n");
}
if (age >= 20) {
printf("Category: Adult 👨💼\n");
}
return 0;
}
🔗 Combining Conditions with && (AND)
The && (AND) Operator
Both conditions must be true:
if (age >= 13 && age <= 19)
TRUE only if age is 13 OR 14 OR 15 OR 16 OR 17 OR 18 OR 19
Real-world example:
if (score >= 90 && attendance >= 95)
Gets honor roll only if BOTH score AND attendance are high
✅ Both True = TRUE
age = 15, condition: age >= 13 && age <= 19
Result: TRUE (both conditions met)
❌ One False = FALSE
age = 25, condition: age >= 13 && age <= 19
Result: FALSE (age not <= 19)
🔐 Password Checker Program
#include <stdio.h>
int main() {
int password;
int secret_code = 1234;
printf("🔐 Enter the secret code: ");
scanf("%d", &password);
if (password == secret_code) {
printf("✅ Access Granted! Welcome! 🎉\n");
printf("🏠 You're now in the secret clubhouse!\n");
}
if (password != secret_code) {
printf("❌ Access Denied! Wrong code! 🚫\n");
printf("🔒 The secret remains protected!\n");
}
return 0;
}
🎯 Test Your Security System:
- Try 1234 → Access Granted!
- Try 1111 → Access Denied!
- Try 5678 → Access Denied!
🛠️ Your Turn: Build Decision Programs!
💡 Coding Challenges
🌡️ Temperature Checker
If temp > 80 → "It's hot!"
If temp < 60 → "It's cold!"
🎯 Score Motivator
If score >= 95 → "Perfect!"
If score < 50 → "Study more!"
🕐 Bedtime Reminder
If hour >= 22 → "Time for bed!"
If hour <= 6 → "Good morning!"
🎮 Game Level Checker
If level >= 10 → "Expert player!"
If level == 1 → "Welcome, beginner!"
🚀 Pick one and let's code it together!
🎲 Preview: Number Guessing Game Logic
#include <stdio.h>
int main() {
int secret_number = 42;
int guess;
printf("🎲 Guess my number (1-100): ");
scanf("%d", &guess);
if (guess == secret_number) {
printf("🎉 Perfect! You got it!\n");
}
if (guess > secret_number) {
printf("📉 Too high! Try a smaller number.\n");
}
if (guess < secret_number) {
printf("📈 Too low! Try a bigger number.\n");
}
printf("The secret number was: %d\n", secret_number);
return 0;
}
🎯 Next Week Preview:
We'll learn if-else statements to make this game even smarter and avoid repeating code!
🏆 Decision-Making Mastery Achieved!
🤔 if Statement Master
⚖️ Comparison Expert
✅ Boolean Logic Pro
🎯 Classifier Builder
🔐 Security System Creator
🎮 Game Logic Designer
Your programs can now think and make decisions! 🧠
You've unlocked the power of intelligent programming!
🏠 Your Decision-Making Programming Mission!
📝 This Week's Challenges:
- 🎓 Complete Grade Classifier - Add more grade categories and motivational messages
- 🌡️ Weather Advisory System - Give clothing advice based on temperature
- 🚗 Speed Monitor - Check if driver is speeding and give warnings
- 🎂 Birthday Party Planner - Suggest party size based on age
- 🏆 Sports Performance Tracker - Classify athletic performance levels
- 🔐 Multi-Level Password System - Different access levels for different codes
🚀 Next Week: Session 8
Advanced Conditionals - if-else and Logical Operators
We'll learn smarter ways to make decisions and handle multiple conditions!
🤔 Think About This Week:
What other decisions would you like your programs to make automatically?
🎊 Excellent work! Your programs are now intelligent decision-makers! 🎊