1305-386-614
(
+
-
)×12 1.25×32×2.5
10.9-(
+9.6÷4)解:(1)1305-386-614,=1305-(386+614),
=1305-1000,
=305;
(2)(
+
-
)×12,=
×12+
×12-
×12,=3+8-10,
=1;
(3)1.25×32×2.5,
=(1.25×8)×(4×2.5),
=10×10,
=100;
(4)10.9-(
+9.6÷4),=10.9-(
+2.4),=10.9-3.2,
=7.7.
分析:(1)运用减法性质解答,
(2)运用乘法分配律解答,
(3)把32化成8×4,再运用乘法结合律解答,
(4)依据四则运算计算方法解答.
点评:本题重点是考查学生合理运用四则运算以及简便算法解决问题的能力.