题目内容
计算下面各题,能简算的要简算.
|
26×(
| ||||||||||||||||
(
|
|
分析:①先算乘法,再利用加法的结合律计算简便;
②把除以
变成乘30,再利用乘法的结合律、分配律计算简便;
③把
变成乘36,再利用乘法的分配律计算简便;
④按运算顺序从左到右依次计算.
②把除以
| 1 |
| 30 |
③把
| 1 |
| 36 |
④按运算顺序从左到右依次计算.
解答:解:①
+
×
+
,
=
+
+
,
=
+(
+
),
=1
;
②26×(
-
)÷
,
=26×30×
-26×30×
,
=300-104,
=196;
③(
-
+
)÷
,
=(
-
+
)×36,
=
×36-
×36+
×36,
=16-15+24,
=25;
④
×
+
×
+3÷19,
=
+
+
,
=
+
,
=
+
,
=
,
=1.
| 3 |
| 8 |
| 5 |
| 8 |
| 2 |
| 5 |
| 3 |
| 4 |
=
| 3 |
| 8 |
| 1 |
| 4 |
| 3 |
| 4 |
=
| 3 |
| 8 |
| 1 |
| 4 |
| 3 |
| 4 |
=1
| 3 |
| 8 |
②26×(
| 5 |
| 13 |
| 2 |
| 15 |
| 1 |
| 30 |
=26×30×
| 5 |
| 13 |
| 2 |
| 15 |
=300-104,
=196;
③(
| 4 |
| 9 |
| 5 |
| 12 |
| 2 |
| 3 |
| 1 |
| 36 |
=(
| 4 |
| 9 |
| 5 |
| 12 |
| 2 |
| 3 |
=
| 4 |
| 9 |
| 5 |
| 12 |
| 2 |
| 3 |
=16-15+24,
=25;
④
| 16 |
| 19 |
| 5 |
| 17 |
| 12 |
| 19 |
| 16 |
| 17 |
=
| 80 |
| 323 |
| 192 |
| 323 |
| 3 |
| 19 |
=
| 272 |
| 323 |
| 3 |
| 19 |
=
| 272 |
| 323 |
| 51 |
| 323 |
=
| 323 |
| 323 |
=1.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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