地球表面积大约是5.1亿平方千米,其中陆地面积是1.49亿平方千米,其余是海洋.海洋的面积是多少亿平方千米?陆地面积比海洋面积少多少亿平方千米?
直接写出得数.×= 1÷= ×= 77:63=÷9= ×= ÷8= 4:2.5=×=
×= 0×= ÷= = = =
= = = == = = == = = == = = =
直接写出得数×3= ×16= ×= (+)×4=×+×= += ÷3= 4÷=
×1= 52﹣42= 0.75﹣0.5= ×= ÷= 125×0.08=0.5+0.02= ÷= ÷= 0.15×6= 12÷0.3= 0÷=