×8
×24
×15+
×9+1
×2×7
.解:(1)
8,=
8×
,=3×
,=1.2;
(2)(
)×24,=
24+
24,=10+21,
=31;
(3)
×15+
×9+1,=
×(15+1)+1,=
16+1,=2+1,
=3;
(4)(
)×2×7,=
+
,=7+2,
=9;
(5)
-
,=
(
),=
,=
;(6)
(
),=
,=1.
分析:(1)运用乘法交换律解答;
(2)(3)(4)(5)运用乘法分配律解答;
(6)按照先算括号里面的,再算括号外面的顺序解答.
点评:(1)运用简便算法解决问题,(2)依据四则运算顺序正确进行计算,是本题考查知识点.