题目内容
(1)0.888×125×73+999×3
(2)
(3)4.44 ÷4
+
÷
+
×4
(4)1+
+
+…+
.
(2)
| 567+345×566 |
| 567×345+222 |
(3)4.44 ÷4
| 5 |
| 8 |
| 31 |
| 37 |
| 25 |
| 111 |
| 36 |
| 37 |
| 11 |
| 25 |
(4)1+
| 1 |
| 1+2 |
| 1 |
| 1+2+3 |
| 1 |
| 1+2+3+…+2007. |
分析:(1)把0.888×125化成0.111×(8×125),再运用乘法的分配律进行简算,
(2)原式化成
,再运用乘法的分配律进行简算,
(3)把除以化成乘以,再运用乘法的分配律进行简算,
(4)原式化成1+
+
+…+
=2×(1-
+
-
+
-
+…+
-
),再进行简算.
(2)原式化成
| 567+345×(567-1) |
| 567×345+222 |
(3)把除以化成乘以,再运用乘法的分配律进行简算,
(4)原式化成1+
| 2 |
| 2×3 |
| 2 |
| 3×4 |
| 2 |
| 2006×2007 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2007 |
| 1 |
| 2008 |
解答:解:(1)0.888×125×73+999×3,
=0.111×(8×125)×73+111×(9×3),
=0.111×1000×73+111×27,
=111×73+111×27,
=111×(73+27),
=111×100,
=11100;
(2)
,
=
,
=
,
=
,
=1;
(3)4.44 ÷4
+
÷
+
×4
,
=4
×
+
×4
+
×4
,
=4
×(
+
+
),
=4
×
,
=9;
(4)1+
+
+…+
,
=1+
+
+…+
,
=2×(1-
+
-
+
-
+…+
-
),
=2×(1-
),
=2×
,
=
.
=0.111×(8×125)×73+111×(9×3),
=0.111×1000×73+111×27,
=111×73+111×27,
=111×(73+27),
=111×100,
=11100;
(2)
| 567+345×566 |
| 567×345+222 |
=
| 567+345×(567-1) |
| 567×345+222 |
=
| 567+345×567-345 |
| 567×345+222 |
=
| 345×567+222 |
| 567×345+222 |
=1;
(3)4.44 ÷4
| 5 |
| 8 |
| 31 |
| 37 |
| 25 |
| 111 |
| 36 |
| 37 |
| 11 |
| 25 |
=4
| 11 |
| 25 |
| 8 |
| 37 |
| 31 |
| 37 |
| 11 |
| 25 |
| 36 |
| 37 |
| 11 |
| 25 |
=4
| 11 |
| 25 |
| 8 |
| 37 |
| 31 |
| 37 |
| 36 |
| 37 |
=4
| 11 |
| 25 |
| 75 |
| 37 |
=9;
(4)1+
| 1 |
| 1+2 |
| 1 |
| 1+2+3 |
| 1 |
| 1+2+3+…+2007. |
=1+
| 2 |
| 2×3 |
| 2 |
| 3×4 |
| 2 |
| 2007×2008 |
=2×(1-
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2007 |
| 1 |
| 2008 |
=2×(1-
| 1 |
| 2008 |
=2×
| 2007 |
| 2008 |
=
| 2007 |
| 1004 |
点评:本题考查了分数、小数四则混合运算的定律,注意算式的特点,灵活运用运算定律进行简算.
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