综合套题九
1、口算（≈为估算）
34 - 15 =	90 × 19 =	1900 ÷ 25 =
8200 ÷ 70 =	40 × 390 =	197 × 71 ≈
260 ÷ 80 =	84 × 3 =	3.4 + 6.9 =
280 ÷ 71 ≈	460 - 80 =	229 + 46 =
2、竖式计算（带*要求验算）
301 ÷ 41 =	*690 ÷ 90 =	284 ÷ 14 =
488 ÷ 81 =	*702 × 33 =	450 ×68 =
3、脱式计算
(207 - 55) ÷ 4	61 × 5 - 256	459 ÷ (9 × 17)