# How Much of the Earth is Ocean Altadena

• Slides: 8

How Much of the Earth is Ocean? Altadena Middle School 6 th Grade Science

What % is Ocean? • Make a prediction – what percent of the Earth is covered by ocean? • Using the grid you have been provided, you and your team must find the actual percent. • You must be able to prove your answer. • Each group member must write down their answer and how they got it on their own piece of paper.

Decide on a Strategy • How will you decide how many squares will count as ocean? • What if a square is only partially covered in ocean? • Should you count the land masses instead? • You must show all of your work on the back of the map grid.

Caribbean Sea Gulf of Mexico Europe Arctic Ocean N. America Asia ic nt la n At cea O Pacific Ocean Pacific Oce Africa S. America Southern Ocean Indian Ocean Australia

x 75 230 =100 Cross Multiply 17, 250 divided by 100= 172. 5 cubic/cm of water 230 - 172. 5 = 57. 5 cubic cm of land area Now prove your answer by counting the whole, half, quarter land squares. What did you come up with? Should be at least five percent plus or minus of 57. 5. Show your work on the back of the grid.

You can either count the water or land squares. Suggested Strategy. • Land = 57. 5 • Whole Squares = • ¾= • ½= • ¼= • 1/8 = Remember to convert your fractions to whole numbers for your final count, i. e. , one hundred ¼’s would = 25 wholes. • Water = 172. 5 • • • Whole Squares = ¾= ½= ¼= 1/8 =

Analysis Questions 1 a. Look at your data: Was your strategy a good way to estimate the % of the earth’s surface covered by water? Why or why not? 1 b. How could you make a better estimate? 2. The water on earth can be found in many places, including lakes, rivers, icebergs, oceans, and even underground. Based on this activity, where do you think most of the water can be found on earth?