题目内容
用简便方法计算
| 125×8.8 | 1.3+4.25+3.7+3.75 | 4.8×1.01 | ||||||||||||
| 17.16-(3.5-2.85) | 3.4×99+3.4 |
| ||||||||||||
|
| 64.2×87+64.2×13. |
(1)125×8.8,
=125×8×1.1,
=1000×1.1,
=1100;
(2)1.3+4.25+3.7+3.75,
=(1.3+3.7)+(4.25+3.75),
=5+8,
=13;
(3)4.8×1.01,
=4.8×1+4.8×0.01,
=4.8+0.048,
=4.848;
(4)17.16-(3.5-2.85),
=17.16+2.85-3.5,
=20.01-3.5,
=16.51;
(5)3.4×99+3.4,
=3.4×(99+1),
=3.4×100,
=340;
(6)
×17+
×8,
=(
+
)×17,
=1×17,
=17;
(7)
×100
,
=
×100+
×
,
=28+
,
=28
;
(8)
÷
+
×
,
=(
+
)×
,
=1×
,
=
;
(9)64.2×87+64.2×13.
=64.2×(87+13),
=64.2×100,
=6420.
=125×8×1.1,
=1000×1.1,
=1100;
(2)1.3+4.25+3.7+3.75,
=(1.3+3.7)+(4.25+3.75),
=5+8,
=13;
(3)4.8×1.01,
=4.8×1+4.8×0.01,
=4.8+0.048,
=4.848;
(4)17.16-(3.5-2.85),
=17.16+2.85-3.5,
=20.01-3.5,
=16.51;
(5)3.4×99+3.4,
=3.4×(99+1),
=3.4×100,
=340;
(6)
| 13 |
| 21 |
| 17 |
| 21 |
=(
| 13 |
| 21 |
| 8 |
| 21 |
=1×17,
=17;
(7)
| 7 |
| 25 |
| 1 |
| 7 |
=
| 7 |
| 25 |
| 7 |
| 25 |
| 1 |
| 7 |
=28+
| 1 |
| 25 |
=28
| 1 |
| 25 |
(8)
| 7 |
| 9 |
| 11 |
| 5 |
| 5 |
| 11 |
| 2 |
| 9 |
=(
| 7 |
| 9 |
| 2 |
| 9 |
| 5 |
| 11 |
=1×
| 5 |
| 11 |
=
| 5 |
| 11 |
(9)64.2×87+64.2×13.
=64.2×(87+13),
=64.2×100,
=6420.
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