Loops and variables — Electronics for kids

Remember

Trace every pass — “write the value of each variable after each time round the loop”

1. count = count + k adds k each time round; after n rounds: start + n × k.
2. A loop inside a loop runs outer × inner times.
3. while (condition) repeats until the condition is false — count the rounds as you trace.

Use it for: Reading and debugging microcontroller programs, counting button presses and coding lessons on loops.

Worked example: 🔁 count = 0 repeat 5 times { count = count + 3 } What is count at the end? → 15

✏️ Practice

Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.

🏁 Lesson 25 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 🔁 Loop Tracer badge when you pass — and a certificate when you finish all 10 lessons of Part 3 · Microcontrollers and IoT. You can still take the test without signing in.

🖨️ Electronics Worksheet: Loops and Variables

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)