如下： 17×40＝680,100－63＝37,3.2＋1.68＝4.88,2.8×0.4＝1.1214－7.4＝6.6,1.92÷0.04＝48,0.32×500＝160,0.65＋4.35＝......
123+25=148123-35=88 248+89=337...146-23=123...155×5=775...456-12=38... 456+45=501...546-457=89.........
