口算.3.2×0.2 1.4×0.4 3.3÷3 1.2÷0.3 5.6÷0.42.5×0.4 1.5×2 7.3+2.7 8.4÷0.7 4.5÷0.90.53﹣0.3 7.8÷6 8.4÷0.21 0.6×0.5 8.1×25.6+3.6 9﹣2.35 0.56÷8 1.23×3 12.5÷0.1.
用简便方法计算: (1)19+199+1999+19999+199999 (2)2367﹣(482+1367) (3)56×125 (4)600÷8÷5 (5)1994﹣1993+1992﹣1991+1990﹣1989.
计算34+77+66.
计算:59+18+41.
简算 1.2×0.25+2.8×0.25 0.65×101 8×1.7×1.25 6.3÷0.25÷4.
用简便方法计算下面各题: ①91000÷280(用竖式) ②48300÷900(用竖式) ③3600÷25 ④35000÷125.