Introduce the lesson by telling students that today you will explore what makes things move. Gently roll a ball away from you and have a student roll it back. Ask students what made the ball roll. Show students another, battery powered toy and ask them what makes this toy move. Hear students ideas and ask clarifying questions. Guide students towards the idea that there is energy stored in the battery that makes the toy move.

Tell students that they now will all get a toy and make very good observations in order to figure out how the toy moves.

**Part 1: Observing wind-up toys**

Show students the wind-up toy that they will work with. Explain how to wind it up and how to let it go inside the crate/box so that it does not fall off the table. Ask students to make and record careful observations. Walk around the classroom and guide students' thinking/explorations by asking some of the following questions:

- How many different parts of the toy can you see? Draw your toy and label the different parts.
- What happens to the different parts of the toy when you turn the winder knob?
- What happens to the different parts of the toy when you let go of the winder knob?
- How do the different parts of the toy work together?
- Try using different numbers of winds. What do you observe?

Give students 10-15 minutes to observe their toys and record their observations. (See attached student handout)

Collect all materials before moving on to the next part of the lesson.

Have students pair up and share their observations and their explanations about how the toy moves with each other.

Then gather the whole group and have some students share out.

Summarize students' observations and explanations and introduce relevant science terms.

Parts of the toy: Winder/winding key, spring, gear, feet

Movement: rotating/rotation, turn, potential/stored energy, kinetic/movement energy, energy transfer

Students record key vocabulary on their worksheet and then use the terms to describe how the wind-up toy works.

**Part 2: What makes it go further**?

Introduce the wind-up wooden cars to the students. Demonstrate how to attach and wind-up the rubber band. Let go of the cart and watch it drive. Have students talk and turn to each other to explain how the car moves, using the science terms from the last lesson. Hear some students report out their ideas.

Ask student how we might be able to make the car go further. Record ideas on board as students share out. Possible ideas might include:

winding up the rubber band more times, using different rubber bands, using more than one rubber band.

As a class, develop a hypothesis for each of their ideas:

"The greater the number of times the rubber band is wound up, the farther the car will go."

"The greater the number of rubber bands used, the farther the car will go."

Tell students that we all will look at one of the hypothesis together (# of turns). Discuss with students how we can test our hypothesis. How can we measure the distance the toy went each time? Show students the meter stick set-up and explain how to make good measurements (placing the front wheels at the 0 of the meter stick, measuring the distance by there the front wheels end up, letting go of the car without pusing it, etc.)

Show students the hand-out and explain that they will first establish a base line, winding up the rubber band 3 times. Tell them that they will do that 3 times/trials. Then students will increase the number of times they wind-up the rubber band and record those results, with 3 trials each time. Students calculate medians.

Students write # of turns and median distance on sticky dots and place it on the class graph on board. Discuss the results as class. Ask students to explain their observations/data. Can we predict how far the toy would go with 12 turns?