4th Grade Science Lesson

Sending Signals: How Waves Carry Information

Shared by A STEM Educator

4th GradeClaim-Evidence-Reasoning4-PS4-345 min

Learning Objective

Students will construct a written CER argument explaining how digitized wave patterns (light or radio) transfer information across distances, citing evidence from hands-on signal activities and real-world examples of fiber-optic and radio wave transmission.

Lesson Overview

Students investigate how wave patterns encode and transfer information — from flashlight signals across the classroom to fiber-optic cables and cell towers — using the CER framework to argue that waves carry coded patterns, not physical matter.

Materials

Flashlights (1 per pair)
Simple signal code chart (provided in card set)
Recording sheets
Rulers
Colored markers
Wave pattern strips (printed cards)
Chart paper for class data
Timer or metronome app
CER writing frame handout

Scaffolded Task Progression

1Task 1

Look at the Wave Pattern Cards (Card Set A). Each strip shows a different pattern of ON (dark bar) and OFF (blank) pulses. Two strips are labeled 'Letter A' and 'Letter B.' Study them and answer: What do you think the pattern of ON/OFF pulses is doing? Write a claim sentence using the starter: 'I claim that waves transfer information by...'

2Task 2

A fiber-optic cable carries internet data as pulses of light. A cell tower sends text messages as radio waves. Make a claim: Do you think these two technologies transfer information the same way or differently? Circle one and write one sentence explaining your thinking BEFORE we collect evidence.

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