Sep28

Understanding and using symbols

It was Monday morning and a sharp corner on a large immovable object (left by another group sharing the space used by the preschool…sound familiar?) unexpectedly turned into a chance to assess the understanding of symbols by one three-year-old.

 

“Ricky” had stepped past the orange cones which surrounded the sharp-cornered plywood platform. I explained that the platform was not ours, the corners were sharp—something to stay away from—and that the orange cones were a symbol for “stop”, that they meant we were not to go past them. “Oh, there should be a sign,” he said, and in a minute he was back with the plastic STOP sign from the bike area.

  He recognized that the cone represented another symbol he was familiar with, a STOP sign, and the command to stop. I wonder at what age he will be able to understand that a globe represents the a planet, Earth, and that the Moon is a sphere?

Published: Sep-28-08 | 0 Comments | 568 Links to this post

Sep24

Preventing misconceptions

As a preschool teacher I try to be aware of how my work might introduce or reinforce misconceptions in my students’ understanding of concepts. In the Perspectives column in the September issue of Science and Children, Michele H. Lee and Deborah L. Hanuscin write about common misconceptions about astronomy, A (Mis)Understanding of Astronomical Proportions? (pg 60-61).

They report on studies that have found that elementary school age children

  • often have difficulty interpreting two-dimensional diagrams which represent three-dimensional space
  • may become confused by ambiguous terms, such as “round earth” which they may think means disk shaped rather than spherical
  • when explaining astronomical phenomena—students who were allowed to manipulate concrete objects produced markedly different student responses from children relying on words alone.

So I will use the word “round” to refer to wheels and plates, and “spherical” to refer to balls and oranges, make 3-D models with playdough instead of drawing diagrams, and provide materials for manipulation when children are asked to tell what they know. It sounds like fun! 

 

Blowing bubbles is an activity where using the word “spherical” comes naturally. The bubble wand opening is a circle and the bubble is a sphere. Children can point to a ball or a flat round disk to show what shape they see when they blow a bubble.

Peggy

Published: Sep-24-08 | 2 Comments | 534 Links to this post

Sep22

The big fish died

The big fish died.  The constant silent presence of the plecostomus—now hiding in the cave, now sucking algae off the aquarium wall—is gone. Donated by a parent who has moved on to high school PTSA duties, the odd fish taught 10 years of preschoolers about its needs: warm water to live in, particular kinds of food, and a place that was quiet and still. Only then would it come out, quickly returning to the cave as children noticed it and the shout went up, “The Big Fish is out, the Big Fish is out!”

Not many children commented on the fish's death, perhaps because school has just started and over the summer they had forgotten about the Big Fish. The tank needs an algae eater. It's time to buy a new little "Big Fish."

Do you have a fish tank in your classroom? How have you used it in teaching? Read more about these cool fish on The Ultimate Pleco Community page.

Peggy

Published: Sep-22-08 | 2 Comments | 771 Links to this post

Sep19

Sky Observations By The Book

Sept coverThe S&C astronomy issue article Sky Observations by the Book (NSTA membership required) presents lessons specifically for teaching young children astronomy concepts with picture books. Authors Kathy Cabe Trundle and Mesut Sackes describe ways to prompt children to notice differences in day and night in pictures to foster understanding about objects in the sky. An important reminder is to evaluate the books first to make sure they do not introduce misconceptions, but keep in mind that flawed books provide the opportunity to help students analyze content.
What surprising comments or questions have your students had about the sky or day and night? Has this led to any enlightening classroom experiences? Share your thoughts in comments below.
Published: Sep-19-08 | 1 Comment | 401 Links to this post

Sep17

Walking Fieldtrips to Draw Nature

A walking fieldtrip can bring much needed outdoor time and opportunity for scientific observation to a class schedule. The objective can be to view the sky, look for birds, find seeds, or to inventory the surrounding environment.

Whether just a walk around the school building or to a natural area several blocks away, a walking fieldtrip is most successful when materials for dealing with unexpected discoveries are brought along.

Here’s a short list of what might be useful:

  • Emergency supplies including emergency phone numbers, cell phone, information on student allergies, non-latex disposable gloves, anti-biotic wipes, band-aids, and a trash bag.
  • Each student should have drawing “pad” of several sheets of paper folded together, and a pencil, for drawing what they see.
  • Students should dress appropriately—wear sunscreen and hat in the middle of the day, and boots and gloves on cold days, for example.
  • Identification books or handouts that may be needed, for birds, trees, insects, clouds, or others.
  • For looking closer bring magnifiers, and for holding small animals (such as insects) bring small clear containers with lids such as carry-out cups or baby-food containers.
  • Young children enjoy using pretend binoculars, made by taping two cardboard tubes together and attaching a wrist loop of yarn with a staple. (See photo below.) Looking through these tubes at objects at any distance will help children focus on details.
  • To make your walk more enjoyable, pack a simple snack such as graham crackers and apple slices.
  • A camera can be used to document the exploration and discoveries.
  • Bring a change of clothes that will fit most children, just in case.

  

Published: Sep-17-08 | 0 Comments | 423 Links to this post

Sep15

Planting Flower Bulbs in the Fall

Planting spring-flowering bulbs connects the seasons of Fall and Spring in the minds of young children as they wait all winter for the bulbs to sprout and to see the flowers blooming in the spring. Following the growth of daffodils or tulips reinforces learning about cycles in nature and noting the sequence of the seasons. Read about planting bulbs on the Clemson University Extension Service webpage.

 

Reading a book, handling a bulb, and seeing what is inside (no tasting!) prepare children to plant a living thing, a flower bulb. Planting a Rainbow by Lois Elhert (Harcourt, 2003), shows bulbs in the ground before sprouting and when blooming. I also like cycle-of-the-season’s books, such as, When This Box is Full by Patricia Lillie (Greenwillow Books, c1993), What Comes in Spring by Barbara Horton (Random House, c1992), Spring: An Alphabet Acrostic by Steven Schnur (Clarion Books, c1999), and Be Blest, a celebration of the seasons by Mary Beth Owens (Simon & Schuster Children's Publishing, 1999).

Here’s a song the class can act out while waiting for a turn to plant, (based on, and to the tune of a traditional song,“Jack in the Box” or make up your own):

Spring flowering bulb, (children curl face down on floor/ground, hiding face)

So safe in the ground,

Way down inside, your little dirt mound, (hands curve over head)

Spring flowering bulb so quiet and still,

Won’t you sprout up? (heads up, stretch arms up high)

Of course I will! (jump up!)

 

I usually explain the word “mound”, and sometimes the word “sprout” before repeating the song.

 

There are seasonal bulbs that grow and bloom in regions that never experience freezing temperatures, such as the “Spider” lily (Hymenocallis sp.) Tropical Giant. Learn about other tropical bulbs in the Amaryllidaceae or the Amaryllis family from the Pacific Bulb Society.

 

Planting the bulbs is a good investment because many species return, year after year, and can be appreciated in many ways. The sweet-sharp-green smell of daffodils takes me back to my childhood.

Peggy

 

Published: Sep-15-08 | 0 Comments | 163 Links to this post

Sep11

Displaying children's science learning

One way I like to show the science learning that goes on in school is by posting my photos or children’s work under headings borrowed from, or inspired by, Barbara Lehn in her book What is a Scientist? (1999. Millbrook Press, with photographs by Carol Krauss). Throughout the year the posted pictures change, and gradually fill up each category (some are harder to capture on paper than others). The last category, “Scientists have fun” usually fills first. Children love to look at the photos and reminisce about past activities.

Here are Lehn’s categories and two I added:

A scientist is a person who asks questions and tries different ways to answer them.

A scientist learns from her senses.

A scientist notices details.

A scientist draws what she sees.

A scientist writes about what happens.

A scientist makes comparisons by measuring.

A scientist must count exactly.

A scientist looks at objects carefully to decide how to sort.

A scientist designs experiments to test predictions.

A scientist experiments by trial and error.

A scientist thinks logically.

A scientist keeps trying over and over.

*A scientist collaborates with others.

*A scientist lists what she thinks she knows.

 A scientist has fun.

 

*My additions.
Published: Sep-11-08 | 0 Comments | 213 Links to this post

Sep10

Scientific literacy comes in handy

The importance of being scientifically literate, that is, being able to sift through the information and decide what seems likely to be true, was brought home (literally) to me this month when I discovered a “colony” of bed bugs in our house. Colony sounds so much nicer, more David Attenborough, than the word “infestation”. While fascinated with the thought that these small animals had been sharing a family member’s bed for at least a month without disturbing the sleeper (what a good system in which the blood-sucker feeds without harming the host!), I immediately went into search-the-bedrooms, search-the-Internet, and destroy-the-insects mode.

 

And there was a lot of information about bed bugs to find. Many pest control companies had primers about this invertebrate which looks something like a small, very flat, lentil shaped roach with a pointy head. Entomology departments of universities were also helpful as was an Australian government document. All sites agreed that bed bugs are rebounding after being controlled with the pesticide DDT. (My mother said that they just used a one-time fumigation “bomb” for their apartment back in the day.) I also learned that the initial clean-up we had done in the colonized bedroom had probably spread the surviving animals to other parts of the house because the pesticide we used repels them. Sure enough, a few days later I woke up on several mornings with really itchy bites that have lasted for more than a week. If only I had read further before acting!

 

My information search resolved into two questions: How did we get them (and not make the same mistake again), and how do we get rid of them now? The bed bugs probably came in on some luggage or a yard-sale stuffed animal, brought by someone who is not sensitive to the bed bug bite and didn’t know they were bringing them. Maybe the bed bugs were still babies, instars who were just a few millimeters of cream-colored exoskeleton looking for a blood meal so they could progress to the next level, that is, molt and move up a nymphal growth stage. The answer to the second question depends on knowing more than most people would like to know about the bed bug life-cycle, and the acceptance of pesticides, and a whole lot of laundering at 60°C. After all my reading I’m still not sure I’m using the correct entomological terms but I do have a plan of action. Because adult bed bugs can survive for 6-7 months without a blood meal, waiting for them to die was not an option.

 

Even the non-commercial internet sites agreed that it is very difficult to eradicate bed bugs from your home without using a knowledgeable pest control service. Some pest control companies I contacted promised to do the job in one day. Here’s where being able to understand the amazing adaptations of bed bugs to their environment was important. The bed bugs can squeeze through outlet and light switch plates into the space between walls, far away from the household spray we had applied. The eggs they lay in the walls and cracks will hatch after the initial pesticide has broken down and is no longer lethal, so a one-time spray is not likely to end the colony. We are using a combination of techniques to kill all the bed bugs in our house beginning with  a whole-house inspection and application of different pesticides on the beds, mattresses, furniture, baseboards, and inside the walls, by a pest control company. We are hot laundering or dry-cleaning all our fabrics and rugs, especially the bedding and things stored near beds, the drive-in fast food stop for bedbugs. Every day we change and wash our sheets to eliminate any eggs that may have been laid by a surviving adult. I just read about using a diatomaceous earth powder as a long-term protection against survivors or newly hatched or surviving bedbugs—apparently it cuts into their exoskeleton and they dry out and die—so it’s back to the internet to see if this method has any research behind it.

Before the pest control company treatment I had to take my box of Tenebrio (mealworm) beetles out of the house. Odd how depending on the setting, one insect is a valued educational tool and another is a dreaded invader that turns the house upside down. That’s the silver lining: accomplishing the long-delayed deep clean and de-cluttering.

Published: Sep-10-08 | 0 Comments | 474 Links to this post