分析:算式(1)(5)(7)(9)(12)可根据四则混合运算的运算顺序计算:先算乘除,再算加减,有括号的要先算括号里面的.
算式(2)(3)(6)(10)可根据乘法分配律计算;
算式(4)(11)可根据加法交换律及结合律计算;
算式(8)可根据一个数减两个数,等于用这个数减去这两个数的和的减法性质进行计算.
解答:解:(1)
×22,
=
;
(2)4.6÷4+7.4×
,
=4.6×
+7.4×
,
=(4.6+7.4)×
,
=12×
,
=3;
(3)95.6×1.8+95.6×8.2,
=95.6×(1.8+8.2),
=95.6×10,
=956;
(4)3.9+4
+6.1+5
,
=(3.9+6.1)+(4
+5
),
=10+10,
=20;
(5)0.15÷0.25+(
+
)
=
+
,
=
;
(6)(
+
+
)×0.24
=
×0.24+
×0.24+
×0.24,
=0.12+0.08+0.06,
=0.26;
(7)3.5×2.7-52.2÷18,
=9.45-2.9,
=6.55;
(8)18
-5.26-4.74,
=18
-(5.26+4.74),
=18
-10,
=8
;
(9)(2
+1
)÷(6-5
),
=
÷
,
=4
;
(10)(25+
)×4
=25×4+
×4,
=100+1,
=101;
(11)
+1
+
+2
=(
+
)+(1
+2
),
=1+4,
=5;
(12)
9+3×4÷2=9
+
×
×
,
=9
+
,
=
+
,
=
.
点评:完成本题要细心,注意小数、分数之间的互化以及通分约分.