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4th grade · Science · Unit 6 of 17

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.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 4.8(A) · energy carried by waves

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 Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 6 of 17 in 4th grade Science, after Energy, Speed & Collisions and before Sound.

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: Texas Education Agency (TEA)

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

    Computers store information as patterns of…

    • colors only
    • rocks
    • 1s and 0s
    • smells

  2. Question 2

    The low point of a wave is the…

    • trough
    • crest
    • peak
    • roof

  3. Question 3

    Which wave has a longer wavelength?

    • A flat line
    • Crests far apart
    • No crests
    • Crests close together

  4. Question 4

    The top of a wave is the…

    • floor
    • base
    • crest
    • trough

  5. Question 5

    Which sends information using light patterns?

    • A drum
    • A traffic light
    • A whistle
    • A doorbell

  6. Question 6

    Two ways to send 'yes' across a field are a flag and a flashlight. To compare them, you test…

    • which is prettier
    • which is easier to see from far away
    • which is heavier
    • which costs more

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