#AP Computer Science Principles: Data & Information Study Guide 🚀

Hey there! Let's get you prepped for the AP CSP exam. This guide is designed to be your go-to resource, especially the night before the test. We'll make sure you're not just memorizing but understanding the key concepts. Let's dive in!

#Big Idea: Data & Information

This unit focuses on how computers represent, store, and process data. It's all about turning raw bits into meaningful information. 💡

This unit is a big deal, accounting for 17-22% of the AP exam, which means you'll likely see around 20 questions on these topics. Make sure you understand the core concepts well!

#2.1 Binary Numbers

#Key Concepts

• Bits: Computers store all data as bits (0s and 1s). Think of them as the fundamental building blocks. 🧱
• Machine Code: Computers use machine code, which operates in the binary system (base-2). This is the language computers understand. 🤖
• Binary Conversion: Any decimal number (base-10) can be represented in binary (base-2), and vice-versa. This is how we translate human-readable numbers to computer-readable numbers. 🔄
• Context Matters: The same sequence of bits can represent different types of data (numbers, text, images) depending on the context. It’s all about interpretation! 🎭
• Abstraction: Hides the complex details of how data is represented, making it easier for us to use computers. Think of it like using a car without needing to know the inner workings of the engine. 🚗
• Analog vs. Digital: Analog data is continuous (like a sound wave), while digital data is discrete (represented by bits). Converting analog to digital involves sampling. 📉➡️📈
• Overflow & Rounding Errors: These errors occur because bits have limitations. Overflow happens when a number is too big to be represented, and rounding errors occur when a number cannot be represented exactly. ⚠️

#Vocabulary

• Data: Raw facts and figures. 📊
• Bits: Binary digits (0 or 1). 🔢
• Number Base: The base of a number system (e.g., 10 for decimal, 2 for binary). 🧮
• Machine Code: The language understood by computers. 💻
• Binary System: Base-2 number system. 0️⃣1️⃣
• Byte: A group of 8 bits. 📦
• Hexadecimal: Base-16 number system, often used for representing binary data more compactly. 0️⃣-9️⃣, A-F
• Abstraction: Hiding complex details. 🙈
• Analog Data: Continuous data. 〰️
• Digital Data: Discrete data. 🔲
• Sampling Technique: Converting analog data to digital data by taking measurements at intervals. 📷
• Overflow Error: When a number is too large to be represented. 💥
• Rounding Error: When a number cannot be represented exactly. ➗