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4th grade · Science · Unit 7 of 8

Waves & Codes

Waves, amplitude, wavelength and sending patterns.

What your child practices

Practices how waves have amplitude and wavelength and can make objects move, and how patterns like codes, flashes and digital signals carry information.

Maine Learning Results learning standard: 4-PS4-1; 4-PS4-3 · patterns in waves, and using patterns to transfer information

How we explain it

Children can open this short lesson before they practice.

  1. Waves have high points (crests) and low points (troughs).
  2. Amplitude is a wave's height. Bigger waves carry more energy.
  3. Wavelength is the distance from one crest to the next.
  4. Patterns like Morse code or digital code can send information.

Example: Which ocean wave has more energy: one 1 m tall or one 3 m tall? The taller wave has a bigger amplitude. Bigger amplitude means more energy. Answer: the 3 m wave

Waves & Codes in Maine

In the Maine Learning Results, this is unit 7 of 8 in 4th grade Science, after Energy, Speed & Collisions and before Rock Layers & Erosion.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Maine Department of Education

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A loud sound has a wave with…

    • a big amplitude
    • a tiny amplitude
    • no amplitude
    • no energy

  2. Question 2

    The top of a wave is the…

    • base
    • trough
    • floor
    • crest

  3. Question 3

    Bigger ocean waves have more…

    • energy
    • color
    • salt
    • fish

  4. Question 4

    Braille uses patterns of…

    • smells
    • raised dots
    • colors
    • sounds

  5. Question 5

    A barcode is a pattern of…

    • lines
    • sounds
    • smells
    • tastes

  6. Question 6

    Morse code for 'SOS' is ··· ––– ···. What carries the message?

    • The color of the light
    • The pattern of short and long signals
    • The paper it is on
    • How loud the ocean is

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