Agua En El Mundo

All
Grades K - 3, 4 - 6
➤ OBJECTIVES • Recognize that there is a lot of water in the world, but that not very much of it can be used for our drinking water and other water supply needs. • Recognize that ground water is a very small percentage of the earth’s water. • Understand how important it is that we take care of our ground water. ➤ INTERDISCIPLINARY SKILLS Science and Math ➤ ESTIMATEDTIME • 30 minutes
(grades K-3)
• 2 hours
(grades 4-6)


the

in the

Wa t e r World


BACKGROUND INFORMATION
ecause water covers three-quarters of the earth’s surface, it might appear that there is plenty to go around and that we will never run out of this valuable resource. In reality, however, we have a limited amount of usable fresh water. Over 97 percent of the earth’swater is found in the oceans as salt water. Two percent of the earth’s water is stored as fresh water in glaciers, ice caps, and snowy mountain ranges. That leaves only one percent of the earth’s water available to us for our daily water supply needs. Our fresh water supplies are stored either in the soil (aquifers) or bedrock fractures beneath the ground (ground water) or in lakes, rivers, andstreams on the earth’s surface (surface water). We use fresh water for a variety of purposes. Agricultural uses represent the largest consumer of fresh water, about 42 percent. Approximately 39 percent of our fresh water is used for the pro­ duction of electricity; 11 percent is used in urban and rural homes, offices, and hotels; and the remaining 8 percent is used in manu­ facturing and miningactivities.

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All the Water In the World

Grades K-3
➤ MATERIALS
❏ Globe ❏ 97 pieces of

TEACHING STRATEGY

FOR

GRADES K-3

Part A - Exploring the Globe 1. Look at the globe with the students. See if they can find where
they live on the globe. Have them point out lakes, rivers, and oceans. Explain that these are called surface waters.

2. Ask the students if theyknow which kinds of waterbodies are
salt water and which are freshwater. Have they ever tasted salt water? Was it good?

uncooked ziti dyed blue, 1 piece dyed red, and 2 pieces dyed green or 100 dixie cups (optional strategy)
❏ Food coloring

3. Ask the students if they think there is more water or land on
the globe. Is there water beneath the surface of the ground that we cannot see onthe globe?

Part B - Demonstrating With Ziti 1. Spread the ziti out on a table. Explain that there are 100 ziti
pieces that represents all (100%) of the water in the world.

2. Using the concept of percentages, ask the students if they know
what the red and green zitis represent. See if they can estimate percentages. Explain that the two green zitis represent water that is stored as ice inglaciers and at the poles (2%). The lone­ ly red ziti represents the fresh water that is available for plants, animals, and people (1% of all the water on the earth). Ask the students what the remaining blue zitis represent. They represent the water that’s in the ocean, 97% of all the water on earth.

3. Ask the students what we should do to take good care of the
water we use in our homes andbusinesses. Use only what we need.

Optional Strategy
Use 100 dixie cups filled with water. Use food coloring (as described above) to indicate ice glaciers and fresh water.

Supplementary Activities
■ Draw a water pie. Have students draw a circle that represents all the water in the world. Have them make pie slices in the circle that represent 97% ocean, 2% glaciers and ice, and 1% freshwater. Color and label the water pie.

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➤

All the Water In the World

■ Make a water necklace. String the ziti (you’ll probably need to have more on hand) on pieces of yarn. Have the students take the necklaces home and explain “all the water in the world” to their families.

Grades 4-6
➤ MATERIALS
❏ Globe ❏ 5 gallons of water ❏ Tablespoons ❏ Container (such as

TEACHING...