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Foundation: Motion, Slope, and Fair Tests

Before You Begin: The Shape of This Phase

Rollers and Sliders

Check Your Understanding: Sorting by Behavior

Steeper, Faster

Check Your Understanding: Nonstandard Measurement

The Unfair Race

Check Your Understanding: The Fairness Rule

Lessons 1–3: children sort rollers from sliders, discover that steeper means faster, and learn the hardest idea in the unit — change only one thing at a time.

The foundation phase: children sort rollers from sliders, discover that steeper ramps mean faster travel, and build the unit's core scientific practice — changing one thing at a time.

What Moves and What Makes It Go

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