### Great Geyser

Standard Met: McREL Science Standard 12 (Understands the nature of scientific inquiry)

What You Need: Bottle of diet soda, small objects such as candy and coins, needle, string, mint-flavored Mentos
What to Do: Tell your students about Yellowstone National Park, a popular vacation destination that is home to hundreds of geysers. Explain that a geyser is a hole in the earth that shoots out hot water and steam. Eruptions occur when boiling water releases steam that jets to the surface. Then tell students you’re going outdoors to make your own geyser.

Carla Jansen, a homeschool teacher from Houston, has students hypothesize what will happen when they drop objects into a bottle of diet soda. After students test their predictions, Jansen uses a needle to string together five mint-flavored Mentos (the white kind with small indentations on the surface). She then drops the string into the bottle and steps back—quickly. The soda will shoot up quite high, so make sure students watch from a distance.

Have your students discuss what they think caused the reaction. Then, explain that soda is carbonated, meaning it contains carbon dioxide. If you shake a soda bottle and open it, the carbon dioxide will rush to the top. “When you drop an object into the drink, you also break the surface tension and release carbon dioxide,” explains Jansen. Mentos produce a dramatic reaction because of the tiny pits on the surface where carbon dioxide bubbles can form. While the cause of the eruption is different from that of a real geyser, if your students can’t get to Yellowstone this summer, a diet-soda geyser is the second-best thing.

### Gone Fishing

Standards Met: CCSS.Math.Content.1.OA.C.6; 2.OA.B.2

What You Need: Printed pictures of fish and of buckets, light-blue construction paper cut into the shape of a pond, paper clips, dowel rods (available at craft or home improvement stores), string, magnets
What to Do: Nancy VandenBerge, who teaches first grade at Boon Elementary in Allen, Texas, does a camping unit at the end of the school year, complete with a fishing trip for math facts. She prints out pictures of fish and writes addition fact sentences (for example, 9 + 6) on them. Then, she attaches a paper clip to the end of each fish. She also prints out pictures of buckets with sums written on them (for instance, a bucket labeled with the number 15). Using real buckets is also an option. VandenBerge then assembles simple fishing poles using dowel rods. She attaches a string to one end of the rod, then puts a magnet on the end of the string to act as a hook. (Magnet letters work well for this because it’s easy to tie the string around them.)

VandenBerge lays out the fish on the floor in their “pond.” Students use their fishing poles to pick up a fish by its paper clip. When they do, they must take the fish off the magnet, solve the math sentence, and then drop the fish into the correct sum bucket. Students continue to do this until they’ve caught their fill for the day. “The kids absolutely loved this activity and couldn’t wait for our next fishing trip—I mean math lesson,” says VandenBerge.

Standards Met: CCSS.ELA-Literacy.CCRA.R.10; W.3

What You Need: Chairs, books