Multiple Choice Questions on Hexadecimal: Computer Science for Kids

📚 Quick Study Guide

• 🔢 Hexadecimal, often shortened to "hex," is a base-16 number system. This means it uses 16 symbols to represent numbers.
• 0️⃣ The symbols include the numbers 0-9, and the letters A-F, representing the decimal values 10-15.
• 🔄 Each hexadecimal digit represents four binary digits (bits).
• ➕ To convert from hexadecimal to decimal, multiply each digit by $16^n$, where $n$ is the digit's position (starting from 0 on the right), then add the results.
• ➖ To convert from decimal to hexadecimal, repeatedly divide the decimal number by 16, noting the remainders. The remainders, read in reverse order, form the hexadecimal number.
• 🎨 Hex codes are commonly used to represent colors in HTML and CSS. For example, #FFFFFF is white.
• 🧮 Example: The hexadecimal number 2A represents $(2 * 16^1) + (10 * 16^0) = 32 + 10 = 42$ in decimal.

🧪 Practice Quiz

1. What base is the hexadecimal number system?

   • A) 2
   • B) 8
   • C) 10
   • D) 16

2. Which of the following is a valid hexadecimal number?

   • A) 123G
   • B) 4567
   • C) 89IJ
   • D) ABCD

3. What decimal number does the hexadecimal number 'A' represent?

   • A) 9
   • B) 10
   • C) 11
   • D) 12

4. What does each hexadecimal digit represent in binary?

   • A) 2 bits
   • B) 4 bits
   • C) 8 bits
   • D) 16 bits

5. What is the decimal equivalent of the hexadecimal number '10'?

   • A) 8
   • B) 10
   • C) 16
   • D) 20

6. In HTML, what are hexadecimal numbers often used for?

   • A) Storing text
   • B) Defining colors
   • C) Performing calculations
   • D) Creating animations

7. What is the hexadecimal equivalent of the decimal number 15?

   • A) E
   • B) F
   • C) 10
   • D) 11