题目内容
怎样算简便就怎样算.
| 6÷ | ||
| [ | 99× | 11.58-(7 |
解:①6÷
-
÷6,
=6×
-
×
,
=20-
,
=19
;
②
×
÷(
-
),
=
÷
,
=
;
③
×3.2+5.6×0.5+1.2×50%,
=0.5×3.2+5.6×0.5+1.2×0.5,
=(3.2+5.6+1.2)×0.5,
=10×0.5,
=5;
④[
-(
+
)]÷
,
=[
-
]÷
,
=
×
,
=
;
⑤99×
,
=(98+1)×
,
=98×
+1×
,
=97+
,
=97
;
⑥11.58-(7
+1.58),
=11.58-7
-1.58,
=11.58-1.58-7
,
=10-7
,
=2
.
分析:①、②、④按运算顺序和计算法则进行计算,③、⑤、⑥可以使用运算定律进行简算.
点评:此题考查整数、分数、小数的四则混合运算,计算要细心,同时注意运用定律进行简算.
=6×
=20-
=19
②
=
=
③
=0.5×3.2+5.6×0.5+1.2×0.5,
=(3.2+5.6+1.2)×0.5,
=10×0.5,
=5;
④[
=[
=
=
⑤99×
=(98+1)×
=98×
=97+
=97
⑥11.58-(7
=11.58-7
=11.58-1.58-7
=10-7
=2
分析:①、②、④按运算顺序和计算法则进行计算,③、⑤、⑥可以使用运算定律进行简算.
点评:此题考查整数、分数、小数的四则混合运算,计算要细心,同时注意运用定律进行简算.
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