| 直接写出得数. 11.3-8.6= | +0.5= | ÷2= | ( + )×12= |
×8+8× = | 1.25× ×8= | (0.18+ )÷9= | - - = |
| 5.38-(1.8+2.38)= | (99.5+250.27)×0= |
| 解:11.3-8.6=2.7, | +0.5= , | ÷2= , | ( + )×12=14, |
×8+8× =12, | 1.25× ×8= , | (0.18+ )÷9=0.12, | - - = , |
| 5.38-(1.8+2.38)=1.2, | (99.5+250.27)×0=0. |
,
,14,12,
,0.12,
,1.2,0.分析:(
+
)×12,
×8+8×
,(0.18+
)÷9=(0.18+
)×
,这三道题运用乘法分配律简算;
-
-
,运用从一个数里连减两个数,就等于减去这两个数的和进行简算;5.38-(1.8+2.38),改写成连减两个数简算;
(99.5+250.27)×0,直接等于0,因为0和任何数相乘都得0;
其他题按照小数、整数和分数的加、减、乘、除的计算方法进行计算即可.
点评:此题考查看算式直接写得数,属于基本的运算,口算时,要看清数据和运算符号再进行计算,能简算的要简算.
+0.5=
÷2=
×8=