| 计算下面各题。(能简算的要简算) | ||||
|
| (1)72.5÷0.5÷20 =72.5÷(0.5×20) =72.5÷10 =7.25 |
(2)4.28×0.4+4.28×1.6 =4.28×(0.4+1.6) =4.28×2 =8.56 |
|
(3)9.2+7.6+10.5 |
(4)1.25×7×0.8×2 =1.25×0.8×7×2 =1×7×2 =14 |
关注公众号回复:奥数答案
即可免费获得密码查看答案

[ ]
[ ]
a. a·b=b·a
-(3
-1
)(2)
+
+
-
(3)
-
-
(4)
-(
+
)