4．计算下面各题，能简便计算的要简便计算．
| 25.6-5$\frac{2}{9}$-3$\frac{5}{9}$-1$\frac{2}{9}$． | 5.17-（1.17+3.05） | 14$\frac{2}{5}$+3$\frac{1}{4}$-3$\frac{2}{5}$+6.75 |
| 1.25×0.45×8×$\frac{1}{45}$ | 4$\frac{1}{5}$-2$\frac{3}{4}$+$\frac{5}{12}$ | 18$\frac{5}{24}$÷2.8×2$\frac{4}{5}$ |
3．直接写得数．
0 154363 154371 154377 154381 154387 154389 154393 154399 154401 154407 154413 154417 154419 154423 154429 154431 154437 154441 154443 154447 154449 154453 154455 154457 154458 154459 154461 154462 154463 154465 154467 154471 154473 154477 154479 154483 154489 154491 154497 154501 154503 154507 154513 154519 154521 154527 154531 154533 154539 154543 154549 154557 199269
| 0.33= | 6.8÷3.4= | 8a-a= | 32÷10%= | 60×50= |
| 3.28+5.2= | 3.14×202= | $\frac{3}{5}$÷$\frac{3}{10}$= | $\frac{7}{20}$×$\frac{5}{21}$= | 5-$\frac{3}{5}$-$\frac{2}{5}$= |
