17．神机妙算，带★号的要验算
| ★243+394= | 201-75= | 830-276= |
| 567+214= | 209+391= | ★700-354= |
16．小明有6张邮票，小刚给他3张后，自己的邮票张数就是小明邮票的2倍．小刚原来有邮票（ ）张．
| A． | 12 | B． | 18 | C． | 21 |
每组画3个●，画4组●．
13．脱口而出．
0 162506 162514 162520 162524 162530 162532 162536 162542 162544 162550 162556 162560 162562 162566 162572 162574 162580 162584 162586 162590 162592 162596 162598 162600 162601 162602 162604 162605 162606 162608 162610 162614 162616 162620 162622 162626 162632 162634 162640 162644 162646 162650 162656 162662 162664 162670 162674 162676 162682 162686 162692 162700 199269
| 40-10= | 15+20= | 35-15= | 42+6= |
| 13-8= | 2×3= | 6×3= | 2×5= |
| 2×4= | 2×6= | 5×6= | 6×6= |
| 5×3= | 4×3= | 3×2= | 4×5-5= |
| 2×3-1= | 3×6+4= | 1×4+4= |
