问题
解答题
| 简便运算． （
23
200.9×10%+2.009×490+0.2009×5000． |
答案
①（
| 2 |
| 71 |
| 1 |
| 69 |
| 25 |
| 71 |
=
| 2 |
| 71 |
| 1 |
| 69 |
| 25 |
| 71 |
=（
| 46 |
| 71 |
| 25 |
| 71 |
| 23 |
| 69 |
=1+
| 1 |
| 3 |
=1
| 1 |
| 3 |
②
| 5 |
| 8 |
| 3 |
| 8 |
=100×（
| 5 |
| 8 |
| 3 |
| 8 |
=100×1，
=100；
③23
| 2 |
| 3 |
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
=
| 71 |
| 3 |
| 7 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 6 |
=
| 497 |
| 6 |
| 1 |
| 2 |
| 1 |
| 6 |
=
| 497 |
| 6 |
| 2 |
| 6 |
=
| 499 |
| 6 |
=83
| 1 |
| 6 |
④200.9×10%+2.009×490+0.2009×5000，
=20.09×1+20.09×49+20.09×50，
=20.09×（1+49+50），
=20.09×100，
=2009．