Utilization
Strategies 
JOURNEY
THROUGH THE SOLAR SYSTEM
By Raymond Lau University of Idaho ITV SERIES MATH TALK: EXPLORING SCALE AND RATION  #114 GRADES 4  6 OVERVIEW In this lesson students will explore the solar system, how to calculate the scale and ratio, and the uses to size and distance. Students will use scale and ratio to measure the actual size and distance of the solar system. Handson activities will engage students in learning. 

LEARNING OBJECTIVES
PLANET CHARTS

MATERIALS




PREVIEWING ACTIVITIES Begin discussion with question such as the following:

FOCUS FOR VIEWING To give students a specific responsibility while viewing that the students are responsible for during and after the viewing to engage students' viewing attention. Have students listen carefully as Maria Lopez in the video discussion what a scale represents. Hand out size and distance tables to students. Also give students pictures of the planets in the solar system. Ask students to watch and write down what they learn about scale and ratio during the video. 



VIEWING ACTIVITIES BEGIN the video at the point just after Maria Lopez asks Buster why he wants to lose weight. STOP the Video after Maria explains to Buster what units of measure are. Ask the students what they think a unit of measure is? Make sure that they understand that every map or scale drawing contains a ratio, or scale. It is the ratio of a length in the map or scale drawing to an actual length. You can use a scale to find actual measures. The scale factor in the scale distance table of the solar system is 1 to 10 billion. As result, the Earth is 150 million km from the Sun. The scaled distance from the Sun is 15m. RESUME the Video and play the section where the sailor goes to the Captain and tells him that their ship is only 10 centimeters from an iceberg. STOP the Video when the Captain explains the difference between a map and the real world. Discuss with the class what the difference the map is from the real world. What is the scale on a map or drawing used for? How do you calculate the distances between places? RESUME the Video and play the section where the Captain states a map that measures New Jersey would have to be as big as the actual New Jersey. STOP the Video when the Captain says 10 centimeters equals 100 kilometers in the real world. Ask students if they now understand how the scale on a map works? Explain to students that maps are drawn by cartographers, who use ratios, proportions, and scale to convert distances on the Earth to distances on paper. Further explain to students that a scale is used to determine distances on a map. For many maps, the scale compares inches or centimeters on a map to miles or kilometers on a real surface or space. To compare distances on a map with actual distances, explain to the students that you use the ratio map distance divided by actual distance. POST VIEWING ACTIVITIES Discuss with the students the information learned in the video. Tell students, "We are going to look more closely at scale and ratioin our journey through the Solar System." Activity 1 Have student's record in their Math/Science Learning Logs how they would make a scale model of the distances between the planets using almost anything as a reference. Students will give their suggestions about the variety of ways to classify the planets of our solar system. Discuss with the students that it is almost impossible to make a scale model of the solar system that is correct in both planetary diameter and distance. Using a 1m Sun and a 5mm Earth, Pluto would be almost one half mile away; using 1 sheet of toilet paper equals 10,000,000 miles. Using the large poster paper, ask students to illustrate in detail the Sun and each of the nine planets on individual sheets (one object per sheet). Have students research and write facts about the object on the back of the poster. They will place all of the posters at the front of the room. Next, ask students to list as many ways as possible to classify (group) them by the appearance of the posters. Ask volunteers to roll out the schoolgrade toilet tissue, marking off the distances to the planets using a scale of one tissue = 10,000,000 miles (refer students to the scaled model of the solar system toilet paper table). Have a student hold a planetposter at each of the appropriate distances. Next, ask students, "In what ways can you classify the planets by their various attributes?" Ask Students how far is the Earth from the Sun? How far is the Earth from Mars? Compare the distances between neighboring planets. Which two are closest together? Which two are farthest apart? As a group, which set of planets is closest togetherthose nearest the Sun or farther out? With other students, hypothesize about the effects of a planet's distance from the Sun. Which planets would be hottest? Which would be coldest? What would the Sun look like from each one? How long would a year be on each planet? Ask students to compare their ideas with each other. Activity 2 Draw an enlarged ruler on the chalkboard and show students which graduations represent millimeters. Explain to students that all data for the diameters of the planets have been rounded (size of planets table). Students will each be given a copy of Sizes of Planets Table, which shows the length of each planet's diameter. The diameter is a line that goes from one side of a planet to the other side through its center. Additionally, the table also shows the sizes for scale models of the planets. Using this scale, 1 millimeter equals 1,000 kilometers. Ask students to look at the pictures in this activity to help you choose the right color clay for your scale model. Students make the ball of clay with the right diameter for each planet. If your planet has rings, cut out the cardboard to make rings. Furthermore, you will need to make the hole in the cardboard a little smaller than your model so that the rings will stick to the scale model. Ask students to put the models in the order shown on the Size of Planets Table. What planet is nearest the Sun? Explain to the students to compare the sizes of the planets, but not the distances between planets. The distances are much greater. How do the models made by other groups' compare with your group's model? Discuss with the students the sizes of the planets. Ask students which is the largest planet? Ask students which is the smallest planet? Is there any pattern in the sizes and order in which the planets are lined up? If so, what pattern do you see? Why are Venus and Earth called sisters? 
POST VIEWING ACTIVITIES (CONT.) Activity 3 (optional)
Ask students to label the objects from the Planetary Relative Size Table with PostIt pads as follows: Mercurymarble; Venuswalnut; Earthgolf ball; Moonraisin; Marsacorn; Jupiterbasketball; Saturnsoccer ball; Uranussoftball; Neptunegrapefruit; Plutobean. Explain to the students that Uranus is slightly larger than Neptune is. If the grapefruit is larger than the softball, switch the labels. Ask the students to arrange the planets in order of increasing size. Does it seem odd to you there are no medium sized planets? Ask the students are all the planets the same size? Is the Moon much smaller than all the planets? Is the Moon a planet? How big should the Sun be on this scale? Explain to the students that the Sun would actually be over nine feet acrossthis is higher than an average classroom ceiling! Scaled Model of Solar System using Tissue Toilet Paper Why use the scale models involving size and distance of objects in the solar system?
EXTENSIONS
Web Sites to Explore: Solar System Trading
Cards Introduction to
the Nine Planets Solar System Exploration:
The Planets 

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