While skiing and sledding may be on your agenda this winter, don't forget to use that snow for something educational, too! Snow-based lessons are perfect for addressing science and math standards at many levels. Begin by explaining the basics of what it takes to make snow. The air above us is filled with particles of dust that serve as condensation nuclei. Water droplets in a cloud settle on condensation nuclei and then begin to freeze, causing flakes of snow to grow. The structure of a snowflake is crystalline, and the temperature directly affects how a snowflake's atoms arrange themselves. When heavy enough, the delicate crystals of ice fall to the earth as snow.

## Geometry from the Sky

A large number of varieties of snowflakes exist; use them to illustrate different geometry concepts. First, share pictures of the different types of snowflakes. Discuss what causes the variations among them. Temperature and supersaturation determine the geometry of each type of snowflake. Use these pictures to discuss some common geometry terms in detail. Have students find a snowflake's midpoint or measure its edges. They can also determine the flake's number of vertices.

Look for opportunities to bring hands-on activities to the math classroom. With some paper and scissors, you can challenge your students to create a symmetrical, hexagonal snowflake. What other types of snowflakes can they successfully cut from paper?

## Investigate Snowflakes in a Classroom Collection

Even though students in early elementary grades are not ready to discuss the geometric details of ice crystals, they will be able to notice the differences among snowflakes. Science standards for early elementary grades often include investigations that require students to use their senses to both describe and classify items based on their physical properties. The next time your area has snow in its forecast during school hours, prepare a lesson on how to study a snowflake.

Besides falling snow, you will need a few materials: hairspray, cardboard, mirrors, a few lids from some kitchen pots and pans, and magnifying glasses. These items will need to chill outdoors for about an hour. Skipping this step will result in the melting of the snowflakes before their shapes can be preserved. Thickly cover the mirror with hairspray, and place it atop the cardboard. Use the cardboard like a tray to prevent your fingers from becoming sticky. Allow several flakes to collect onto the mirror. Before too many fall onto the mirror and overlap each other, cover the mirror with the lid. The covered mirror must dry outside for about an hour before it can be brought indoors.

Although the flakes will have disappeared, imprints of their images will remain visible on the mirror. Students can get a better look at the each snowflake by using the magnifying glasses. Have students generate a few questions about the snowflakes based on what they see. If the weather allows, have your class create additional snowflakes on different days, especially on snowy days that are colder or warmer than the temperature was on the day when the first specimens were collected. Discuss how the flakes in each collection differ.

## Snowfall Data Wall

Students are often taught to represent and interpret data in late-elementary school and junior high school mathematics. Plot points on a chart with your class to show the amount of snow that falls in your area each day this winter. Students can measure snowfall themselves or record the measurements reported by local TV or radio weathermen. Students can use the data to calculate the average snowfall during a particular period of time. Compare this with data from previous winters.

Discuss what will be communicated to the audience. Will the x-axis track days or hours and the y-axis inches or feet? Besides providing accurate information in a logical way, students need to know how weather affects our daily lives. To be proficient in interpreting the chart, they can correlate the data to how the weather affected the community. From this, predictions can be made about future forecasted snow showers. At what point will roads be treated or cleared? How many inches must fall before students shovel? Miss school?

## No Snow This Winter?

If you live in a climate where you won't see a single flurry, you may feel like you are missing out. Try the next-best-thing with your class: make your own snow! It's a simple and easy process. You'll need to mix water with sodium polyacrylate. Sodium polyacrylate is a substance found in disposable diapers. You may also be able to find this ingredient at your local gardening center. Gardeners use it to maintain soil moisture. When sodium polyacrylate is mixed with water, artificial snow is formed. It's a gelatinous combination that can be thinned by adding additional water. It will keep for a long time; just stick it in a refrigerator or freezer and add water when it seems to be drying out. Students will be surprised at the similarities they find between their fake snow and the real thing.

## Emergency Preparedness

No matter the age or grade level of a classroom, teachers can review health and safety practices when snow is in the forecast. Teach kids about the symptoms of frostbite and hypothermia. Snow is beautiful, but it can be portentous, too. Remind kids to stay visible. This includes wearing bright clothing and remembering to turn on the headlights! Our teens don't have much experience behind the wheel, and they must be mindful of how a little snow can cause big problems on frozen roadways.