四升五年级数学暑假作业小数简便运算

四升五年级数学暑假作业小数简便运算


简介:
399.6×9-1998×0.8 = 399.6×9-1998×2×0.4 = 399.6×9-399.6×4 = 399.6×5 =1998 25.9-6.47-3.53 =25.9-(6.47+3.53) =25.9-10 =15.9 0.5×7.49×2 =0.5×2×7.49 =1×7.49 =7.49 0.45×101 =0.45×(100+1) =0.45×100+0.45×1 =45+0.45 =45.45 8.8×12.5 =1.1×(8×12.5) =1.1×100 =110 25×0.125×8 =25×(0.125×8) =25×1 =25 5.34×99+5.34 =5.34×(99+1) =5.34×100 =534 98.9×100.1 =98.9×(100+0.1) =98.9×100+98.9×0.1 =9890+9.89 =9899.89