题目内容
计算下面各题,能简算要简算
|
(
|
99×
| ||||||||||||||||||
(32+
|
|
2-
|
分析:(1)先把除法变成乘法,再运用乘法分配律简算;
(2)先算小括号里面的减法,再算括号外的乘法;
(3)先把99分解成98+1,再用乘法分配律简算;
(4)先把除法变成乘法,再运用乘法分配律简算;
(5)先算小括号里面的减法,再算括号外的除法,最后算减法;
(6)先算除法,再根据连续减去两个数等于减去这两个数的和求解.
(2)先算小括号里面的减法,再算括号外的乘法;
(3)先把99分解成98+1,再用乘法分配律简算;
(4)先把除法变成乘法,再运用乘法分配律简算;
(5)先算小括号里面的减法,再算括号外的除法,最后算减法;
(6)先算除法,再根据连续减去两个数等于减去这两个数的和求解.
解答:解:(1)
×
+
÷
+
,
=
×
+
×
+
×1,
=(
+
+1)×
,
=2×
,
=
;
(2)(
-
)×
,
=
×
,
=
;
(3)99×
,
=(98+1)×
,
=98×
+1×
,
=7+
,
=7
;
(4)(32+
)÷4,
=(32+
)×
,
=32×
+
×
,
=8+
,
=8
;
(5)
÷
×(
-
),
=
÷
×
,
=
×
,
=
;
(6)2-
÷
-
,
=2-
-
,
=2-(
+
),
=2-2,
=0.
| 1 |
| 4 |
| 3 |
| 8 |
| 3 |
| 4 |
| 8 |
| 3 |
| 3 |
| 8 |
=
| 1 |
| 4 |
| 3 |
| 8 |
| 3 |
| 4 |
| 3 |
| 8 |
| 3 |
| 8 |
=(
| 1 |
| 4 |
| 3 |
| 4 |
| 3 |
| 8 |
=2×
| 3 |
| 8 |
=
| 3 |
| 4 |
(2)(
| 1 |
| 4 |
| 1 |
| 10 |
| 1 |
| 3 |
=
| 3 |
| 20 |
| 1 |
| 3 |
=
| 1 |
| 20 |
(3)99×
| 7 |
| 98 |
=(98+1)×
| 7 |
| 98 |
=98×
| 7 |
| 98 |
| 7 |
| 98 |
=7+
| 7 |
| 98 |
=7
| 7 |
| 98 |
(4)(32+
| 4 |
| 7 |
=(32+
| 4 |
| 7 |
| 1 |
| 4 |
=32×
| 1 |
| 4 |
| 4 |
| 7 |
| 1 |
| 4 |
=8+
| 1 |
| 7 |
=8
| 1 |
| 7 |
(5)
| 10 |
| 9 |
| 5 |
| 6 |
| 5 |
| 4 |
| 7 |
| 12 |
=
| 10 |
| 9 |
| 5 |
| 6 |
| 2 |
| 3 |
=
| 4 |
| 3 |
| 2 |
| 3 |
=
| 8 |
| 9 |
(6)2-
| 6 |
| 7 |
| 9 |
| 14 |
| 2 |
| 3 |
=2-
| 4 |
| 3 |
| 2 |
| 3 |
=2-(
| 4 |
| 3 |
| 2 |
| 3 |
=2-2,
=0.
点评:本题考查了基本的简算的方法,这些常用的简便运算的方法,要熟练掌握,灵活运用.
练习册系列答案
相关题目