November 01, 2005

observing spider webs

Did yoy know that you can tell the species of spider from the pattern of the web?

The garden orb weaver on the right spins a classic orb web, but there are many variations. Samuel Zschokke has a great selection of spider web images at spider web construction gallery. I put together a slideshow for the kids from that web site and few others. I also put copies of webs on the walls from How to Know the Spiders by Barbara Kaston, et al., which has fantastic spider web illustrations. The book is not exactly second grade material (most of the spiders are not drawn with legs!), but the webs are illustrated so clearly that my son was able to identify a Zygiella web in our living room.

The Zygiella is so distinctive with clear gaps in its orb-weaver spiral that when I showed them the slideshow of webs, they nicknamed it the "pacman" web. They were all very excited when one boy found this web in the schoolyard and easily recognized it. It was science in action! The assignment was to search out the schoolyard for webs and draw one (or more) in their notebooks. One remarked that he had never seen a living spider in its web.

Another fun activity that we did at home with a friend was
catching a web. On our outing, it was way more fun for the grown-ups. It may be better for older kids. (The web site recommends 8 and up.) Our 7-year-olds lacked the attention span, but they liked looking at the captured webs afterwards.

On the whole, the spider project with the class was a great success. They really liked going outside and looking at the schoolyard in a new way. It was fun for them to learn something about identifying spider webs and to apply it immediately.

Posted by Sarah at 10:53 AM

September 27, 2005

observations

For the first science class of second grade, we made observations using all five senses. This lesson was adapted from "Confection Connection" which I found in Teaching Science Process Skills, which has many excellent activities for grades 6-8.

Since I teach science in the morning, I didn't want to use the candy idea from the original lesson. I chose raspberries for the mystery objects. Before class, I used two different sized cups to hide one raspberry for each student and set them on a side table.

I told the class that I would be coming in every couple of weeks to do science with them. I asked them if they could tell me what a scientist is:
- someone who discovers new things about the world
- someone who finds new sea creatures in the ocean
- someone who studies volcanos
- someone who makes new things by mixing chemicals
- someone who learns about animals and the ocean
- someone who makes potions
I pointed out that scientists don't call their mixtures potions anymore, but that hundreds of years ago, sometimes people were afraid when other people discovered new things about the world. What we now call science was often called magic, and the people who were called witches were often people who had discovered new things about our world.

I asked the students to name the five senses: sight, hearing, taste, touch, and smell. Then after telling them they couldn't peek and to wait until we told them to start the first step, we handed out the cups and worksheets.

The worksheet had six questions:
1) What do you hear inside of the cup?
2) Close your eyes and open the cup, what do you smell?
3) Close your eyes. Take the object out of the cup. Feel its texture and its shape. Put it back in the cup, close the cup and open your eyes. Draw what you think it looks like.
4) Open the cup. Draw what you see.
5) Place the object in your mouth. Describe what you taste.
6) Which of your five senses would you least like to live without?

Our awesome second grade teacher took my draft of the wroksheet and improved the wording a bit and added cool pictures of an ear, nose, eye, and so forth, next to each question.

It was great fun. It was very hard for the kids just to write their observations and not shout out their discoveries, but it was good for them to try to write down their own ideas. When listening to the object in the cup, a lot of the kids thought it was a grape or a bouncy ball. After feeling it, many mistook it for a strawberry -- they had the extra hint of getting red juice on their hands.

At the end, I got them share what words they used to describe their observations. One boy said that the raspberry looked like a brain. I asked how did it look like a brain: was it the same color? the same shape? the same size as a brain? This wrap-up time was also a good time to get the quiet kids to talk. Since they had all written on their worksheet, I knew everyone had a answer. I called on everyone who hadn't yet raised their hands. It turned out to be a great way to get everyone involved.

Posted by Sarah at 01:04 PM

August 20, 2005

centrifugal force

This is a great outdoor activity and was one of the class favorites of the year.

Preparation:
- one paper cup for each student (use a strong one, like those made for hot drinks
- Tie a string to the cup by making two hole near the top across from each other and create a loop. Make it just long enough so that if a child holds the string with their arm relaxed, the cup will not touch the ground.
- for each child: one penny, one small ball
- a large bucket of water

By now, we've learned about different kinds of forces forces. I asked the kids to name some (magnetism, gravity). I demonstrated gravity by dropping a penny in a cup. Gravity makes the penny stick to the bottom of the cup. If I turn the cup upside-down, the force of gravity makes the penny fall out. I told the class that I had a challenge for them. Did they think they could make it so when the cup is upside-down the penny didn't fall out? They all believed it was impossible. I told them that I would give them the materials for an experiment and that they were to try to keep the penny in the cup when the cup is upside-down. I pointed out that attached to each cup is a piece of string -- that's a hint.

We then went outside and let them each play with a penny, cup and string. Some of them learned by swinging the cup that the penny would stay inside; some of them twirled the cup on the string; and, of course, once most of the kids had figured it out they all saw how easy it was. There was a great joy of discovery.

I proceeded to give them the next challenge. They all exchanged the penny for a ball. This one went fairly quickly. They all had fun exploring this new concept with a different prop.

When they had all mastered the second challenge, I explained that they now had to keep water in the cup. There were a few doubters, but they all were excited to give it a try. Everyone was successful and they kept at it till most of the cups had gotten soggy or fallen apart from the strain.

Posted by Sarah at 08:53 AM