19．用竖式计算．
| 56×9= | 72÷4= | 5×480= | 658×4= |
| 80÷3= | 403×6= | 389×7= | 96÷8= |
17．口算．
0 162608 162616 162622 162626 162632 162634 162638 162644 162646 162652 162658 162662 162664 162668 162674 162676 162682 162686 162688 162692 162694 162698 162700 162702 162703 162704 162706 162707 162708 162710 162712 162716 162718 162722 162724 162728 162734 162736 162742 162746 162748 162752 162758 162764 162766 162772 162776 162778 162784 162788 162794 162802 199269
| 30×9= | 90÷3= | 60÷2= | 600×5= |
| 7×200= | 4×300= | 25×4= | 36÷3= |
| 3×800= | 64÷8= | 7×500= | 60÷6= |
| 80÷4= | 600×7= | 35÷5= | 6×400= |