脱式计算(7/16-0.25)x17/18=(7/16-4/16)x17/18=3/16x17/18=1/15x17/6=17/90以上为该算式计算全过程
(7/16-0.25)*17/18=(7/16-1/4)*17/18=(7/16-4/16)*17/18=3/16 * 17/18=1/16 * 17/6=17/96