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苏科版七年级数学下册53页第8题:地球上海洋总面积约为3.6×108km2,海洋总面积是地球表面积的百分之几?按海洋的海水平均深度3.7×103m计算,求地球上海水的体积(用科学记数法表示).教学参考书给出的解答是:71%,1.332×10×109=(3·6×108×3·7)km3.此题看似简单,乍看毫无问题.编者在求水的体积时,把它近似地看成截面约为3.6×108km2,高为3.7km的长方体(柱体)的体积.其实不然!此水截面太大,又
Suksu Edition Grade 7 Mathematics Next Volume 53 Page 8 Problem 8: The total area of the ocean on the Earth is approximately 3.6×108km2. The total area of the ocean is a few percent of the surface area of the Earth. Calculate the Earth’s average depth by 3.7 × 103m. The volume of water in Shanghai (represented by scientific notation). The answer to the teaching reference book is: 71%, 1.332×10×109=(3·6×108×3·7)km3. This question seems simple. At first glance there was no problem. When the editor asked for the volume of water, the editor saw it approximately as a rectangular parallelepiped (cylindrical) with a section of about 3.6×108km2 and a height of 3.7km. In fact, this water section was too large.