解:(1)3.8+3.17÷(22+9.7),
=3.8+3.17÷31.7,
=3.8+0.1,
=3.9;
(2)68÷[0.5×(7.5-0.7)],
=68÷[0.5×6.8],
=68÷3.4,
=20;
(3)352-162÷36×24,
=352-4.5×24,
=352-108,
=244;
(4)[
-(
-
)]×
,
=[
-
]×
,
=
×
-
×
,
=
-
,
=
,
=
;
(5)(
+
+
)÷
,
=(
+
+
)×36,
=
×36+
×36+
×36,
=12+6+4,
=22;
(6)
×[
÷(
×
)],
=
×[
÷
],
=
×
,
=
.
分析:(1)先算小括號(hào)里面的加法,再算括號(hào)外的除法,最后算加法;
(2)先算小括號(hào)里面的減法,再算中括號(hào)里面的乘法,最后算括號(hào)外的除法;
(3)先算除法,再算乘法,最后算減法;
(4)先算小括號(hào)里面的減法,然后運(yùn)用乘法分配律簡算;
(5)運(yùn)用乘法分配律簡算;
(6)先算小括號(hào)里面的乘法,再算中括號(hào)里面的除法,最后算括號(hào)外的乘法.
點(diǎn)評(píng):1.一個(gè)算式里,如果含有兩級(jí)運(yùn)算,要先做第二級(jí)運(yùn)算,后做第一級(jí)運(yùn)算.
2.一個(gè)算式里,如果有括號(hào),要先算小括號(hào)里的,再算中括號(hào)里面的.