Variables, Loops and Bugs: teacher key

How Coding Works, grade 4 edition, written for 4th grade. Learn the building blocks programmers use: instructions, loops, variables, choices, functions and lists. Then see how bugs are hunted down.

Read the book. Print this page for the key.

Questions and answers

1. What can a loop do?
   • Repeat a set number of times, or until something happens (answer)
   • Turn a bug into an insect
   • Name a variable
2. What does a variable hold?
   • A bug
   • A value that can change (answer)
   • A recipe
3. Which is a syntax bug?
   • A typing mistake in the code (answer)
   • A real insect
   • A new game
4. Why does a computer need a programmer's instructions?
   • It likes lists
   • It cannot think for itself (answer)
   • It is made of bugs
5. A program takes an umbrella only if it is raining. What is that?
   • A loop
   • A list
   • A conditional (answer)

Words

• algorithm: list of steps
• loop: a repeat
• variable: changing box
• conditional: if test
• function: named code
• debugging: fixing mistakes