题目内容
能简算的用简便方法计算.
(
|
| 204÷
| ||||||||||||||||
| [
| 99×
|
(1)(
-
÷2)×
=(
-
)×
=
×
=
;
(2)
-(
+
)×
=
-
×
=
-
=
;
(3)204÷
+204×9
=204×91+204×9
=204×(91+9)
=204×100
=20400;
(4)
×3.2+5.6×0.5+1.2×50%
=0.5×3.2+5.6×0.5+1.2×0.5
=0.5×(3.2+5.6+1.2)
=0.5×10
=5;
(5)[
-(
+
)]÷
=[
-
]÷
=
÷
=
;
(6)99×
=(98+1)×
=98×
+1×
=97+
=97
.
| 2 |
| 5 |
| 2 |
| 5 |
| 5 |
| 3 |
=(
| 2 |
| 5 |
| 1 |
| 5 |
| 5 |
| 3 |
=
| 1 |
| 5 |
| 5 |
| 3 |
=
| 1 |
| 3 |
(2)
| 15 |
| 16 |
| 7 |
| 12 |
| 1 |
| 6 |
| 1 |
| 2 |
=
| 15 |
| 16 |
| 3 |
| 4 |
| 1 |
| 2 |
=
| 15 |
| 16 |
| 3 |
| 8 |
=
| 9 |
| 16 |
(3)204÷
| 1 |
| 91 |
=204×91+204×9
=204×(91+9)
=204×100
=20400;
(4)
| 1 |
| 2 |
=0.5×3.2+5.6×0.5+1.2×0.5
=0.5×(3.2+5.6+1.2)
=0.5×10
=5;
(5)[
| 5 |
| 3 |
| 2 |
| 5 |
| 3 |
| 4 |
| 31 |
| 4 |
=[
| 5 |
| 3 |
| 23 |
| 20 |
| 31 |
| 4 |
=
| 31 |
| 60 |
| 31 |
| 4 |
=
| 1 |
| 15 |
(6)99×
| 97 |
| 98 |
=(98+1)×
| 97 |
| 98 |
=98×
| 97 |
| 98 |
| 97 |
| 98 |
=97+
| 97 |
| 98 |
=97
| 97 |
| 98 |
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