How Many Gallons Are in an Ocean?

Teacher Notes:

• If you prefer, have students find the volume of every body of water in the table by using a spreadsheet. They could have columns for the volume in square miles, square feet, square inches, and gallons.
• If you prefer, have students research the dimensions of other bodies of water in the world, the U.S., or their state using the Internet. They could find the volumes of lakes in their state by estimating the surface area using a map and finding information about the depth of the lake.

Procedure for the Activity

Answers:

Step 1  area in square miles = 113,500 = 1.135 x 10⁵, area in square feet = 1.135 x 10⁵(5.280 x 10³)(5.280 x 10³)= 31.641984 x 10¹¹; volume in cubic feet = 31.641984 x 10¹¹(1.21 x 10²) = 38.28680064 x 10¹⁵ = 3.828680064 x 10¹⁴ cubic feet or 382,868,006,400,000 cubic feet

Step 2  3.828680064 x 10¹⁴ cubic feet(12 in.)(12 in.)(12 in.) = 6615.959151 x 10¹⁴ = 6.615959151 x 10¹⁷ cubic inches; 6.615959151 x 10¹⁷ ÷ 231 = 0.0286405158 x 10¹⁷ = 2.86405158 x 10¹⁵ gallons or 2,864,051,580,000,000 gallons of water

Step 3  See students’ work.

Step 4  volume of pool = 25 x 15 x 5 = 1875 cubic feet; 3.828680064 x 10¹⁴ cubic feet ÷ 1875 = 0.0020419627 x 10¹⁴ or 2.0419627 x 10¹¹ pools, or written in standard notation, 204,196,270,000 pools

Wrapping Up the Activity

See students’ work.