练习十七,（选自教材,P56-57,）,0.60.4+0.40.52+0.60.52+0.4,=0.24+0.4+0.6+0.4,=1.64,（,m,2,）,答：一共要准备,1.64m,2,的塑料板。,200.242.5=12,（立方米）,52012=6240,（块）,答：一共要用,6240,块砖。,31.511.33,5.99(,吨,),答：装载的煤大约有,5.99,吨。,容积为：,50301.8=2700(m,3,),需要时间：,2700200=13.5,（时）,答：要注深,1.8,米的水大约需要,13.5,时,.,15055=3750(cm,3,),37507.8=29250,（,g,）,=29.25kg,答：这段方钢有,29.25kg,。,体积：,30.52=3(m,3,),表面积：,(30.5+0.52+32)2,=(1.5+1+6)2,=17,（,m,2,）,答：体积是,3m,3,，表面积是,17m,2,。,容积：,143=12(cm,3,),体积：,1.0541.05311.05=13.9(cm,3,),（,14+13,）,2+34=26(cm,2,),1.0541.058=35.28(cm,2,),26+35.28=61.28(cm,2,),