Materials: blocks or a cardboard box, toy cars or marbles, paper

These super-simple ideas show that what goes up must come down!

• Gather a few small items of different weights, such as a crayon, a crumpled piece of paper, a tissue, and a stuffed toy. Have your child drop each item from shoulder height. Do some items fall faster than others?

• Help your child build a ramp from blocks, the side of a cardboard box, or other household items. Roll a toy car down it. It rolls from the top down by itself, but how about from the bottom up? No—it has to be pushed!

• Make a paper airplane together and test it out! How far can it fly? No matter how far it goes, it always lands somewhere. That’s because of gravity!