18．列竖式计算．
| 1.04-0.89= | 0.068+0.482= | 10-9.05= |
| 100-64.55= | 97.6+32.44= | 50.6-12.88= |
17．9.999保留二位小数是（ ）
| A． | 10 | B． | 9.99 | C． | 10.00 |
13．脱式计算，能简算的要简算．
| 355+260+140+245 | 735×（700-400÷25） | 58×58+58×42 |
| 645-180-245 | 382×101-382 | 720÷8÷9． |
12．直接写出得数．
0 137253 137261 137267 137271 137277 137279 137283 137289 137291 137297 137303 137307 137309 137313 137319 137321 137327 137331 137333 137337 137339 137343 137345 137347 137348 137349 137351 137352 137353 137355 137357 137361 137363 137367 137369 137373 137379 137381 137387 137391 137393 137397 137403 137409 137411 137417 137421 137423 137429 137433 137439 137447 199269
| 12+88= | 25×8= | 100-35-25= | 1000÷125= |
| 65+35= | 8×125= | 235-（35+27）= | 37+63+98= |
| 300÷（25×4）= | 23×99+23= |