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Run it in class

How do collision history and source shape sand grains?

Show of hands — before you project anything

Predict first: do you think sand was always tiny, or was it once big rock? How could the SHAPE of a grain help us tell?

  • A Way more than you'd guess
  • B About what you'd guess
  • C Way less than you'd guess

Count the votes out loud. Hold them to it — then watch.

Project it (fullscreen)

Discussion prompts

  • Predict first: do you think sand was always tiny, or was it once big rock? How could the SHAPE of a grain help us tell?
  • Predict first: send a soft rock and a hard rock down the same river — which one turns into sand faster, and why?
  • Some beaches are white, pink, or even black. Predict what got smashed up to make each color before you look it up.

Where it shows up in real life

  • Rounded, smooth grains in beach or river sand, versus the sharp edges of crushed gravel
  • A pebbly mountain stream where rocks are bigger and more jagged than at the river's mouth
  • A white tropical beach made largely of crushed coral and shells instead of rock

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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