①( + )×24 | ②1080-63.58-36.42 | ③( + )÷( - ) |
④ ×[ -( - )] | ⑤ + ÷ ×![]() | ⑥9.05×37+64×9.05-9.05. |
+
)×24=
×24
×24=8+6
=14;
②1080-63.58-36.42
=1080-(63.58+36.42)
=1080-100
=980;
③(
+
)÷(
-
)=


=
;④
×[
-(
-
)]=
×(
)=
×
=
;⑤
+
÷
×
=
+
×
×
=
+
=
;⑥9.05×37+64×9.05-9.05
=9.05×(37+64-1)
=9.05×100
=905.
分析:①⑥可用乘法分配律简算;②按照减去两个数等于减去这两个数的和来简算;③④⑤按照先算小括号里的,再算乘除,最后算加减的运算顺序计算.
点评:乘法分配律是最常用的简算方法,注意它的变形后的使用.