"Timber." A huge tree crashes to the forest floor. What could have been strong enough to cut down such a big tree? A wedge, that's what!" What is a wedge? What are some examples of wedges? How do we use wedges? Turns out a wedge can be the front end of a ship cutting its way through ice and a wedge can be a slice of yummy cake. The book ends with an experiment you can do yourself to see how a wedge works. Also in this series, PULL, LIFT AND LOWER, ROLL, SLOPE AND SLIDE, SCOOP, SEESAW AND RAISE, TIRES, SPOKES AND SPROCKETS.