6．笔算，带▲的验算
| 563+344= | 889+142= | 674+235= |
| 924-677= | ▲895-447= | 71×65= |
| 278×12= | 56×37= | ▲517÷9= |
3．口算
0 159620 159628 159634 159638 159644 159646 159650 159656 159658 159664 159670 159674 159676 159680 159686 159688 159694 159698 159700 159704 159706 159710 159712 159714 159715 159716 159718 159719 159720 159722 159724 159728 159730 159734 159736 159740 159746 159748 159754 159758 159760 159764 159770 159776 159778 159784 159788 159790 159796 159800 159806 159814 199269
| 30×50 | 80×60 | 20×90 | 60×30 | 7.8+0.5 |
| 14×50 | 11×80 | 80×30 | 1.4-0.8 | 3.8-1.9 |