综合套题九
1、口算（≈为估算）
1700 ÷ 25 =	2.8 + 8.9 =	70 - 38 =
310 ÷ 20 =	390 + 70 =	903 × 27 ≈
180 ÷ 93 ≈	20 × 460 =	447 - 29 =
3700 ÷ 60 =	83 × 2 =	80 × 84 =
2、竖式计算（带*要求验算）
3752 ÷ 51 =	247 ÷ 42 =	728 ÷ 74 =
40 ×816 =	*710 ÷ 60 =	*804 × 88 =
3、脱式计算
540 ÷ (18 × 5)	(290 - 47) ÷ 9	794 + 44 ÷ 2