考點(diǎn):分?jǐn)?shù)的四則混合運(yùn)算
專題:運(yùn)算順序及法則
分析:①②④按照四則混合運(yùn)算的順序進(jìn)行計(jì)算即可.
③⑥運(yùn)用加法的交換律及結(jié)合律進(jìn)行計(jì)算即可.
⑤⑦⑨⑩運(yùn)用乘法的分配律進(jìn)行計(jì)算即可.
⑧運(yùn)用乘法的交換律及 結(jié)合律進(jìn)行計(jì)算即可.
解答:
解:①
+
=
+=2
②2÷
×
=2×
×=
×=
③
+
-
+
=(
-)+(
+)
=0+1
=1
④2.25×
=
=1
⑤0.15×1.2+3.8×15%
=0.15×1.2+3.8×0.15
=0.15×(1.2+3.8)
=0.15×5
=0.75
⑥178.5-36.6-63.5
=178.5-63.5-36.6
=115-36.6
=78.4
⑦25×
×
×
=(25×
)×(
×
)
=10×
=2.5
⑧17×2÷17×2
=(17÷17)×(2×2)
=1×4
=4
⑨(
-
)÷
=(
-
)×12
=12×
-
×12
=3-2
=1
⑩
×2011
=
×(2010+1)
=
×2010+1×
=2009+
=2009
點(diǎn)評:本題考查了學(xué)生通過約分對分?jǐn)?shù)四則混合運(yùn)題目進(jìn)行簡算的能力.