题目内容
简便计算.
(1)13
-5.8+3
+4.2 (2)7.7÷1
+0.75×4
(3)(
-0.25+
)×2.4(4)2
×4.625+6
×250%-2.5.
(1)13
| 5 |
| 7 |
| 2 |
| 7 |
| 1 |
| 3 |
| 3 |
| 10 |
(3)(
| 5 |
| 6 |
| 1 |
| 3 |
| 1 |
| 2 |
| 3 |
| 8 |
(1)13
-5.8+3
+4.2
=(13
+3
)-5.8+4.2
=17-5.8+4.2
=15.4;
(2)7.7÷1
+0.75×4
=7.7÷
+0.75×4
=7.7×
+0.75×4
=7.7×0.75+0.75×4
=0.75×(7.7+4
)
=0.75×(7
+4
)
=0.75×12
=9;
(3)(
-0.25+
)×2.4
=(
-
+
)×2.4
=
×2.4-
×2.4+
×2.4
=5×0.4-0.6+0.8
=2-0.6+0.8
=2.2;
(4)2
×4.625+6
×250%-2.5
=2.5×4.625+6.375×2.5-2.5
=2.5×(4.625+6.375-2.5)
=2.5×8.5
=21.25.
| 5 |
| 7 |
| 2 |
| 7 |
=(13
| 5 |
| 7 |
| 2 |
| 7 |
=17-5.8+4.2
=15.4;
(2)7.7÷1
| 1 |
| 3 |
| 3 |
| 10 |
=7.7÷
| 4 |
| 3 |
| 3 |
| 10 |
=7.7×
| 3 |
| 4 |
| 3 |
| 10 |
=7.7×0.75+0.75×4
| 3 |
| 10 |
=0.75×(7.7+4
| 3 |
| 10 |
=0.75×(7
| 7 |
| 10 |
| 3 |
| 10 |
=0.75×12
=9;
(3)(
| 5 |
| 6 |
| 1 |
| 3 |
=(
| 5 |
| 6 |
| 1 |
| 4 |
| 1 |
| 3 |
=
| 5 |
| 6 |
| 1 |
| 4 |
| 1 |
| 3 |
=5×0.4-0.6+0.8
=2-0.6+0.8
=2.2;
(4)2
| 1 |
| 2 |
| 3 |
| 8 |
=2.5×4.625+6.375×2.5-2.5
=2.5×(4.625+6.375-2.5)
=2.5×8.5
=21.25.
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