问题描述:
计算①28.67×67+3.2×286.7+573.4×0.05
②
1 |
1×5 |
1 |
5×10 |
1 |
10×15 |
1 |
15×20 |
1 |
20×25 |
③
1 |
2 |
1 |
4 |
1 |
8 |
1 |
31 |
1 |
62 |
1 |
124 |
1 |
248 |
1 |
496 |
④
4 |
7 |
12 |
13 |
1 |
7 |
1 |
7 |
4 |
13 |
最佳答案:
(1)28.67×67+3.2×286.7+573.4×0.05,
=28.67×67+32×28.67+28.67×(20×0.05),
=28.67×(67+32+1),
=28.67×100,
=2867;
(2)
1 |
1×5 |
1 |
5×10 |
1 |
10×15 |
1 |
15×20 |
1 |
20×25 |
=
1 |
5 |
1 |
5 |
1 |
5 |
1 |
10 |
1 |
10 |
1 |
15 |
1 |
15 |
1 |
20 |
1 |
20 |
1 |
25 |
=
1 |
5 |
1 |
5 |
1 |
5 |
1 |
25 |
=
1 |
5 |
1 |
5 |
4 |
25 |
=
29 |
125 |
(3)原式=(1-
1 |
2 |
1 |
2 |
1 |
4 |
1 |
4 |
1 |
8 |
1 |
31 |
1 |
31 |
1 |
62 |
1 |
62 |
1 |
124 |
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