Fourth Grade · Science · week 17

Design: message across the room

Design, build, and test a device or method that sends a coded message across a room using a wave, light or sound, as the carrier.

This week combines everything from the unit so far: waves carry energy and can carry information if you attach a code to the pattern. Your challenge is to design a working way to send a real message all the way across a room, using either light (flashlight flashes) or sound (claps, taps, or a whistle) as your wave.

A successful design needs three things working together: a code your receiver already knows, a way to reliably send the pattern across the whole distance, and a way for the receiver to clearly notice and record each signal. If the message arrives across the room correctly decoded, your design has done its job as a real communication system.

📋 For the teacher
Teach it (10–15 min):
  • Set your child, and a sibling or you, at opposite ends of a room or hallway to actually send and receive a message using their week 15 code.
  • Introduce a real obstacle partway through, background noise for a sound code, or a light already on in the room for a light code, and see if the design still works.
  • Ask them to identify the weakest part of their system after testing and to propose one specific fix.
  • Keep the final test honest: the receiver should decode without being told the message in advance.
Talk about it:
  • Did your message arrive correctly decoded on the first try? What happened?
  • What was the weakest part of your communication system, and how did you improve it?
  • Why is testing with someone who does not already know the message so important?

Mastery looks like: They can design and test a working system that sends a coded message across a room using light or sound, adjusting the design based on real test results.

Common stumbles: Skipping a real end-to-end test with an actual receiver; using signal patterns too similar or too fast for the receiver to reliably tell apart.

Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
Records attendance + 15 min of Science for this learner.
← Back to todayAll coursesYear planner