考點:分?jǐn)?shù)的簡便計算,分?jǐn)?shù)的四則混合運算
專題:運算順序及法則
分析:(1)(2)(3)(8)(10)(11)(12)(13)(15)(16)(18)運用乘法分配律解答,
(4)(5)(7)(9)(14)(19)按照先算第二級運算,再算第一級運算,如果只含有同一級運算,按照從左到右順序計算,有括號先算括號里面的順序計算解答,
(17)運用乘法交換律解答.
解答:
解:(1)17×
=16×
+1×
=9+
=9
;
(2)(
+
)×32
=
×32+
×32
=24+20
=44;
(3)
×
+
×
=
×(
+
)
=
×1
=
;
(4)
×
×16
=
×16
=2
;
(5)
+
×
=
+=
;
(6)44-72×
=44-30
=14;
(7)
×8×25
=6×25
=150;
(8)24×
=23×
+1×
=21+
=21
;
(9)
×
×
=
×
×
=
×
=
;
(10)43×
+
=(43+1)×
=44×
=20;
(11)
×
+
×
=(
+
)×
=1×
=
;
(12)(
-
)×24
=
×24-
×24
=18-8
=10;
(13)(
+
)×
=
×
=
;
(14)
+
×
=
+
=
;
(15)(
-
)×12
=
×12-
×12
=3-2
=1;
(16)
×13+
=
×(13+1)
=
×14
=13;
(17)
×
×39
=
×39×
=
×
=2
;
(18)3
×28
=3×28+
×28
=84+16
=100;
(19)
×
×
=
×
=
.
點評:本題考查知識點:(1)依據(jù)四則運算計算方法正確進(jìn)行計算,(2)正確運用簡便方法解決問題.