Which One Works Best?
Aligned to K-2-ETS1-3 — Next Generation Science Standards.
What this lesson teaches
We can test two things that do the same job to see which one works better.
Worked examples
Example 1
We pour water into a paper cup and a plastic cup to see which one holds it without leaking.
Example 2
We drop a feather and a rock to see which lands first, then try again to be sure.
Example 3
We test one thing at a time. If we change the cup and the water at once, we will not know which change mattered.
Practice questions
- Test two toy cars down a ramp and see which one rolls farther.
- Try two kinds of paper as a paper airplane and watch which flies better.
- Tell a grown-up which one you think won and why.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
¿Cuál funciona mejor?
Podemos probar dos cosas que hacen el mismo trabajo para ver cuál funciona mejor.
Ejemplo 1: Echamos agua en un vaso de papel y en uno de plástico para ver cuál la aguanta sin gotear.
Ejemplo 2: Dejamos caer una pluma y una piedra para ver cuál llega primero, y lo intentamos otra vez para estar seguros.
Ejemplo 3: Probamos una cosa a la vez. Si cambiamos el vaso y el agua al mismo tiempo, no sabremos cuál cambio importó.
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