| 12.06-0.5+0.5×0.2 | 7.4+0.38+0.22+2.6 | ![]() | . |
=12.06-0.5+0.1,
=12.02;
(2)7.4+0.38+0.22+2.6,
=(7.4+2.6)+(0.38+0.22),
=10+0.6,
=10.6;
(3)(
+
)×45,=
×45+
×45,=30+6,
=36;
(4)350÷
-350×
,=350×
-350×
,=350×(
-
),=350×
,=140.
分析:(1)先算乘法,再算加法和减法;
(2)运用加法交换律与结合律简算;
(3)运用乘法分配律简算;
(4)把除法给位乘法,运用乘法分配律简算.
点评:考查了小数、分数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算律简便计算.

.