解：采用分配律，原式=68×0.11+8.9×6.8=6.8x1.1+6.8x8.9=6.8x（1.1+8.9）=6.8x10=68
图
68×0.11+8.9×6.8＝68*0.11+0.89*（10*6.8）＝68*0.11+0.89*68＝68*（0.11+0.89）＝68*1＝68
68.......
