口算:
| 40×6= | 56×4= | 130×6= | 19×5= |
| 13×5= | 12×7= | 150×2= | 230×4= |
| 180×3= | 120×4= | 500×10= | 140×7= |
| 15×8= | 80×9= | 210×6= | 16×5= |
递等式计算,能简算的要简算,并写出主要计算过程.
| ①45.6÷2.5÷0.4 | ②13.45÷0.5-7.9 | ③2.4×101 | ④3.9×2.5÷15. |
| 40×6= | 56×4= | 130×6= | 19×5= |
| 13×5= | 12×7= | 150×2= | 230×4= |
| 180×3= | 120×4= | 500×10= | 140×7= |
| 15×8= | 80×9= | 210×6= | 16×5= |
| ①45.6÷2.5÷0.4 | ②13.45÷0.5-7.9 | ③2.4×101 | ④3.9×2.5÷15. |