1．列竖式计算
| 3.56+7.5= | 3-2.08= | 2.25×48= |
| 44÷50= | 5.06×1.3= | 0.72÷1.5= |
| 35.5×180= | 50.4÷0.48= | 40.5÷0.18= |
20．直接写出得数．
| 1.2×0.5= | 0.81+0.9= | 1.3÷0.125÷8= | 48÷4.8= |
| 0.25×8= | 15.7-7.2= | 6.4+1.06= | 2.5×0.7×4= |
19．甲乙两数的商是0.4，如果被除数扩大10倍，除数缩小10倍，那么商是（ ）
| A． | 0.4 | B． | 4 | C． | 40 | D． | 400 |
15．直接写得数．
0 128347 128355 128361 128365 128371 128373 128377 128383 128385 128391 128397 128401 128403 128407 128413 128415 128421 128425 128427 128431 128433 128437 128439 128441 128442 128443 128445 128446 128447 128449 128451 128455 128457 128461 128463 128467 128473 128475 128481 128485 128487 128491 128497 128503 128505 128511 128515 128517 128523 128527 128533 128541 199269
| 2.5×4﹦ | 0.3÷0.1﹦ | 1.6÷0.8= | 7.2÷0.6= | 3.9÷3.9= |
| 1.8×0.8= | 1.2÷0.3﹦ | 5.6÷8﹦ | 1.25×3.3×0﹦ | 2-0.64-0.36﹦ |