六下数学小升初简便计算易错题专练 1.递等式计算(能简算的要简算) 18.08﹣(1.08+79)﹣29 =18.08﹣1.08﹣79﹣29 =17﹣(79+29) =16 7949×0.875+79÷1.6 =(80﹣59)×78+79÷85 =80×78﹣59×78+79×58 =70 12.4﹣2.4÷415÷2.5 =12.4﹣2.4×154÷2.5 =12.4﹣0.6×15÷2.5 =8.8 4.2÷[25×(2.8﹣1.05)] =4.2÷[25×1.75] =4.2÷0.7 =6 2.请用简便方法计算下面各题。 19999+9999×9999 =10000+9999+9999×9999 =10000+9999×(9999+1) =10000+9999×10000 =10000×(9999+1) =100000000
