The term "scientific method" refers to a set of steps used by scientists to answer questions about the world around them. Scientists begin by asking a question, completing research and formulating a hypothesis or prediction. Next, they complete an experiment, make observations and draw conclusions. Elementary students may find this process confusing, but through hands-on, engaging activities, they quickly become familiar with it.

## Penny Experiment

Predicting how many drops of water will fit on a penny utilizes second-graders' critical thinking skills while introducing them to the scientific method. Given a penny to examine, students can make a prediction, or hypothesis. Pairs of students using an eyedropper and a cup of water can complete this experiment on their own, counting the number of drops collected on both sides of the penny and recording their observations in a chart.

After the experiment, students discuss their results and attempt to draw conclusions based on their observations. The teacher can also introduce the concept of cohesion by leading a class discussion on how the water droplets cling together.

## Paper Airplanes

Students use engineering skills as they design a paper airplane to travel the furthest distance. Working in groups, they brainstorm ideas about successful airplane designs before performing research via books, pictures of airplanes or the Internet.

After creating a hypothesis by sketching their designs, the second-graders each build an airplane using a piece of notebook paper. Participating in an airplane-toss competition and experimenting with their ideas demonstrates how design affects flight patterns. After observing the results, the teacher can lead a discussion about which airplanes were most successful and explain the concepts of force, motion and air resistance.

## Aluminum Foil Boats

Students practice the steps of the scientific method while determining which type of boat design can hold the most weight. After a class discussion and brainstorming session, students work in small groups to sketch or write about their designs for a boat made from a 5-by-5-inch square of aluminum foil.

The experiment uses a small tub of water to hold each boat, upon which the students drop paper clips -- one at a time -- until the boat sinks. By recording their data on a chart and trying several designs, they'll determine which boat is strongest. After making verbal conclusions through sharing their results with the class, they can complete a written summary of why some designs prove more practical than others.

## Student-Directed Learning

Most of the time, adults design experiments for the classroom, but letting second-graders plan their own experiments and formulate questions encourages creativity and increases student participation. In an activity suggested by Exploratium.edu, students receive an ice-filled balloon to explore and serve as inspiration for questions to write down on small sticky notes.

The teacher helps students categorize their questions as testable or untestable, encouraging them to think about all aspects of the scientific method and if they could use their questions to design an experiment. Such an activity teaches that questioning remains at the core of the scientific method and that observation and experimentation provide the answers.