做口算2.5×9=?你是怎么想的?把你的思考过程写出来.
用脱式计算.(除不尽时四舍五入保留两位小数) ①13.7×0.25×8②18﹣(1.4+1.25×2.4) ③(10.5+27.8)÷(5.2﹣2.5)④4.2÷[8×(6.34﹣4.59)].
脱式计算.(能简算的要简算) 7.02×1.021.125÷0.09 2001×0.54+2001×0.460.64×0.25+0.75 0.78÷26+0.5×0.02[2.8﹣2.8×(2.8﹣2.8)]÷0.7 8×[1÷(3.2﹣2.95)]33.4﹣26.465÷(2.6+4.1)
脱式计算,(能简算的要简算) 25×7.6×0.823.7﹣3.9+6.3﹣6.12.5×64×1.25. 1÷(1﹣0.98)5.9×7.8+5.9×1.2+5.926.8×0.25﹣6.8÷4.
计算下面各题,注意运用简便方法. 30.3÷[(1.3+1.2)×0.6]0.59×7.2﹣7.2×0.39 1.25×7.4×81.6﹣0.2÷5×40.
递等式计算.(能简算的要简算) ①2.5×3.2×1.25②6.06﹣3.5×0.24 ③60.4﹣(10+9.6÷0.4)④2.3×3.2+2.3×6.8.