整理与练习(2)1. 3.14x( 0.6÷2)2x3 =3.14x0.09x3 =0.8478(立方米)答:挖这口水井一共需要挖土0.8478立方米。2. 3.14x(2÷2)2x12x1/3+3.14x(2÷2)2x12 =12.56+37.68 =50.24(厘米)答:体积一共是50.24立方厘米。3. 0.6÷2=0.3(厘米) 3.14x0.32x1 =3.14x0.09x1 =0.2826(立方厘米) 50÷0.2826≈176.928(次)(用舍去法为176次)答:这支鞋油可以用176次。【请关注零五网:https://www.05wang.com/】 4. 3.14x102x2 =3.14x100x2 =628(立方厘米)答:这个铁块的体积是628立方厘米。5. 用铁皮3.14x122+3.14x12x2x35 =3.14x144+3.14x12x2x35 =452.16+2637.6 =3089.76(平方厘米)盛水: 3.14
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