题目内容
| 计算下面各题,怎样算简便怎样算. 226÷2+14×5 |
8×(
| ||||||||
| 1÷(1-0.9) |
|
分析:(1)先算除法和乘法,再算加法;
(2)利用乘法分配律简算;
(3)先算减法,再算除法;
(4)调整运算顺序,先算除法,再算乘法.
(2)利用乘法分配律简算;
(3)先算减法,再算除法;
(4)调整运算顺序,先算除法,再算乘法.
解答:解:(1)226÷2+14×5
=113+70
=183;
(2)8×(
-
)
=8×
-8×
=6-3
=3;
(3)1÷(1-0.9)
=1÷0.1
=10;
(4)
×
÷
×
=
÷
×
×
=1×
×
=
.
=113+70
=183;
(2)8×(
| 3 |
| 4 |
| 3 |
| 8 |
=8×
| 3 |
| 4 |
| 3 |
| 8 |
=6-3
=3;
(3)1÷(1-0.9)
=1÷0.1
=10;
(4)
| 4 |
| 5 |
| 6 |
| 7 |
| 4 |
| 5 |
| 6 |
| 7 |
=
| 4 |
| 5 |
| 4 |
| 5 |
| 6 |
| 7 |
| 6 |
| 7 |
=1×
| 6 |
| 7 |
| 6 |
| 7 |
=
| 36 |
| 49 |
点评:混合运算的关键是抓住运算顺序,正确按运算顺序计算,适当运用运算定律计算.
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