题目内容
计算(能简算的一定要简算)
(1)
×2.96÷2
÷(1
×1.48)×4
(2)
×1997+
×1995.
(1)
| 3 |
| 7 |
| 1 |
| 11 |
| 5 |
| 7 |
| 2 |
| 11 |
(2)
| 12 |
| 17 |
| 5 |
| 17 |
分析:(1)先根据除法的性质,去掉括号,然后把除法变成乘法,再运用乘法交换律和乘法结合律简算;
(2)先把1997分解成1995+2,运用乘法分配律简算,再运用加法交换律简算,然后再次运用乘法分配律简算.
(2)先把1997分解成1995+2,运用乘法分配律简算,再运用加法交换律简算,然后再次运用乘法分配律简算.
解答:解:(1)
×2.96÷2
÷(1
×1.48)×4
,
=
×2.96÷2
÷1
÷1.48×4
,
=
×
×
×
×
×
,
=(
×
)×(
×
)×(
×
),
=
×2×2,
=
;
(2)
×1997+
×1995,
=
×(1995+2)+
×1995,
=
×1995+
×2+
×1995,
=
×1995+
×1995+
×2,
=1995×(
+
)+
×2,
=1995×1+
×2,
=1995+
,
=1996
.
| 3 |
| 7 |
| 1 |
| 11 |
| 5 |
| 7 |
| 2 |
| 11 |
=
| 3 |
| 7 |
| 1 |
| 11 |
| 5 |
| 7 |
| 2 |
| 11 |
=
| 3 |
| 7 |
| 74 |
| 25 |
| 11 |
| 23 |
| 7 |
| 13 |
| 25 |
| 37 |
| 46 |
| 11 |
=(
| 3 |
| 7 |
| 7 |
| 13 |
| 74 |
| 25 |
| 25 |
| 37 |
| 11 |
| 23 |
| 46 |
| 11 |
=
| 3 |
| 13 |
=
| 12 |
| 13 |
(2)
| 12 |
| 17 |
| 5 |
| 17 |
=
| 12 |
| 17 |
| 5 |
| 17 |
=
| 12 |
| 17 |
| 12 |
| 17 |
| 5 |
| 17 |
=
| 12 |
| 17 |
| 5 |
| 17 |
| 12 |
| 17 |
=1995×(
| 12 |
| 17 |
| 5 |
| 17 |
| 12 |
| 17 |
=1995×1+
| 12 |
| 17 |
=1995+
| 24 |
| 17 |
=1996
| 7 |
| 17 |
点评:本题考查了较复杂的简便运算,注意要把几个运算定律结合使用.
练习册系列答案
相关题目