Desi's Marble Ramp

Desi wants a marble to roll into a tray. She makes a ramp from a long strip of wood. A ramp is a path that slants up or down.

Desi puts one end on a tall block. The ramp is steep. One end is much higher than the other. The marble rolls off the tray!

"How can I fix it?" asks Desi.

"Try a low block," says Pop. Now the ramp has a gentle slope. One end is just a bit higher. The marble rolls into the tray.

Desi grins. She draws her ramp.

Her page has the heading "My Ramp." A caption under the picture says, "A low block helps!"