题目内容
下面各题,怎样算简便就怎样算.
①0.0618×160+6.18×8.4
②
×[
÷(
-
)]
③
×6+
+4×
+
×4
④2.5×1.6(用三种不同算法简算)
①0.0618×160+6.18×8.4
②
| 8 |
| 9 |
| 3 |
| 4 |
| 7 |
| 16 |
| 1 |
| 4 |
③
| 4 |
| 7 |
| 4 |
| 7 |
| 1 |
| 10 |
| 9 |
| 10 |
④2.5×1.6(用三种不同算法简算)
(1)0.0618×160+6.18×8.4,
=6.18×1.6+6.18×8.4,
=(1.6+8.4)×6.18,
=10×6.18,
=61.8;
(2)
×[
÷(
-
)],
=
×[
÷
]
=
×4,
=3
;
(3)
×6+
+4×
+
×4,
=
×(6+1)+(
+
)×4,
=4+4,
=8;
(4)2.5×1.6,
=2.5×(4×0.4),
=2.5×4×0.4,
=10×0.4,
=4;
2.5×1.6,
=2.5×(1+0.6),
=2.5×1+2.5×0.6,
=2.5+1.5,
=4;
2.5×1.6,
=2.5×(2×0.8),
=5×0.8,
=4.
=6.18×1.6+6.18×8.4,
=(1.6+8.4)×6.18,
=10×6.18,
=61.8;
(2)
| 8 |
| 9 |
| 3 |
| 4 |
| 7 |
| 16 |
| 1 |
| 4 |
=
| 8 |
| 9 |
| 3 |
| 4 |
| 3 |
| 16 |
=
| 8 |
| 9 |
=3
| 5 |
| 9 |
(3)
| 4 |
| 7 |
| 4 |
| 7 |
| 1 |
| 10 |
| 9 |
| 10 |
=
| 4 |
| 7 |
| 1 |
| 10 |
| 9 |
| 10 |
=4+4,
=8;
(4)2.5×1.6,
=2.5×(4×0.4),
=2.5×4×0.4,
=10×0.4,
=4;
2.5×1.6,
=2.5×(1+0.6),
=2.5×1+2.5×0.6,
=2.5+1.5,
=4;
2.5×1.6,
=2.5×(2×0.8),
=5×0.8,
=4.
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