综合套题九
1、口算（≈为估算）
381 - 29 =	350 ÷ 51 ≈	80 - 68 =
920 - 90 =	830 ÷ 30 =	1800 ÷ 25 =
67 × 4 =	7.7 + 9.8 =	901 × 42 ≈
26 × 80 =	230 × 70 =	6500 ÷ 40 =
2、竖式计算（带*要求验算）
417 ÷ 81 =	*490 ÷ 30 =	980 ×44 =
295 ÷ 11 =	*806 × 49 =	481 ÷ 69 =
3、脱式计算
845 + 66 × 4	8 × (70 + 41)	480 ÷ 3 ÷ 10