Sand Dollars and Math on the Beach

The 5's of the Sand Dollar

The sand Dollar is shaped like a Pentegon

Cool Facts about Sand Dollars

The sand dollar's mouth has a jaw with five teethlike sections to grind up tiny plants and animals. Sometimes a sand dollar chews" its food for fifteen minutes before swallowing. It can take two days for the food to digest.

-Monterrey Bay Aquarium

How Old is your Sand Dollar?

Calculating the Age of a Sand Dollar

Look for the hard white sand dollars along the tideline amongst the seaweed and shells. These are the exoskeletons or the dead remains of sand dollars. Look for growth rings along the edges of these plates.

Separate your sand dollar tests (the dead "shell" of the sand dollar) by age. What is the average at which your sand dollars died?

You can use your underwater tablet to make a graph representing the average lifespan of the sand dollars you found on the beach.

Sand Dollar Printout

You can often find the dead "shell" of a sand dollar (called a "test") washed up on sandy beaches. If you break open a test, there are many hard, loose, white pieces; these were the teeth of the Sand Dollar.

- Enchanted Learning Software

Intertidal invertebrates of California

Scientists can age a sand dollar by counting the growth rings on the plates of the exoskeleton. Sand dollars usually live six to 10 years.

- Google Book Search

Sand Dollar Symmetry

Symmetry at the Beach

Sand Dollar Symmetry

Like other echinoderms, sand dollars have fivefold radial symmetry (pentamerism). Unlike sea urchins, the sand dollar has secondary bilateral symmetry, with a front and back as well as a top and bottom. The anus is toward the rear rather than on the top.

Pentamerism

This variant of radial symmetry (also called pentaradial and pentagonal symmetry) arranges roughly equal parts around a central axis at orientations of 72° apart.

Poem of Sand Dollar Symmetry

Such Touchstones

His stoop borrows the memory of a child
hunkered over jewels on the tide line,
as if he's been lifting seaweed from mother of pearl,
discovering sand dollar symmetry,
or poking the bubblegum globe
of a Portuguese man-o-war,
watching its varicose tendrils firing their last
electric volleys in receding waves.
Switched on by his finds, how he would beguile.

But though the lucid days are few
and in between the seven ages blur,
such touchstones, if infrequent, still occur.
He points to a sandpiper and to a secret cue
digs me in the ribs, goes shy, and smiles.

Paul Maddern

Sand Dollar Worksheets

Sand Dollar Worksheets

Sand Dollar Activity Page - Find The Twins

What Are Echinoderms?

In this science printable about invertebrates, students will evaluate true/false statements about echinoderms and use reference materials to identify drawings of a sea cucumber, a starfish, a sand dollar, and a sea urchin.

Marine Biology Game

I Am a Marine Invertebrate.

Here are the names of the animals found in this quiz.

Sand Dollar Habitat

Where can you find Sand Dollars?

These sand dollar pictures have a Creative Commons License.

These sand dollars are at the bottom of the ocean about 30 feet below the surface in a spot where the water is calm.

30 feet is much deeper than the height of a human. How deep is that? Take your tape measure and measure thirty feet in the sand. Now have your dad lie down at the starting point of where you measured. Is he 30 feet tall? Now add another member of your family with their feet touching your dad's head. How many family members will it take to measure 30 feet.

An exercise like this will help everyone to understand just how deep the sand dollars are.

Sand Dollars by legrave1
View other Sand dollar Posters

Sand Dollars Alive

What are sand dollars? Children who find them buried in beach sand often think that they may be mermaids' money washed up from the ocean.

Sand dollars live on top of or just beneath the sandy surface or muddy areas of the sea floor at thirty to forty-foot depths.

Sand dollars are abundant on the sandy bottom of deeper waters around the world

Sand dollars sometimes congregate in groups of thousands. In quiet waters they are tilted up on their edge waiting for floating food items. In rough waters they lay flat or burrow in. To fight fast-moving currents, the adults grow heavier skeletons while the young sand dollars swallow heavy grains of sand to weight themselves down.

Read more: Sand Dollars Alive - Habitat, Predators: Mermaids' Money and Doves are Nicknames for Sand Dollars - http://marine-life.suite101.com/article.cfm/sand_dollars#ixzz0CEvSp0VA

How to Preserve and Harden a Sand Dollar

Cape Cod Sand Dollar, currency of the sea!

In order to achieve a white and clean looking specimen it is important to soak your sand dollar in fresh water first. Follow the steps below to preserve your live sand dollar.

1. As soon as possible after discovering your sand dollar soak it in fresh water. The water will discolor and begin to give off a foul oder so change it frequently until it stays fairly clear.
2. Soak your sand dollar in a solution of bleach and fresh water for 5-10 minutes
3. Remove from solution, rinse in freshwater and let dry.
4. Repeat steps 2 and 3 if needed, but remember each soaking in bleach weakens the sand dollar. Time in the sun will also whiten your sand dollar.

To harden sand dollars, mix together equal parts white glue and water and apply to both sides using a sponge brush.

Sand Dollar Cookies

Sand Dollar Fractions

Etsy :: Dmari :: Plum Island Cookie Company Sand Dollar Cookies

Plum Island Cookie Company is a small specialty bakery offering delicious Gourmet French Butter cookies hand-designed into exquisite Sand Dollars and other buttery sweets! The delicate vanilla-scented butter cookies come boxed with fou...

Cape Cod Sand Dollar, currency of the sea!

Sand Dollar Cookie Ingredients:

* 3/4 C butter
* 1 cup sugar
* 2 eggs
* 1/2 Teas. vanilla
* 2 1/2 C flour
* 1 Teas. baking powder
* 1 Teas. salt

Procedure:

1. Mix the butter, sugar, eggs, and vanilla thoroughly.
2. Add flour, baking powder and salt.
3. Mix and chill the dough for one hour.
4. Roll out the dough on a floured surface to 1/8"-1/4" thick.
5. Cut out cookies using a 3" cutter or water glass.
6. Place cookies on ungreased cookie sheet.
7. Draw a star in the center of each cookie with a dull knife.
8. Bake at 400 degrees for 7 mins.