怎样算简便就怎样算.(1)4.32+5.43+6.68 (2)15.17﹣6.8﹣3.2 (3)34.82﹣(4.82+15.2)(4)15.27+4.72﹣5.28 (5)4.02﹣3.5+0.98 (6)5.8﹣4.5+5.8﹣4.5.
唐老鸭家与米老鼠家来回有423米,米老鼠共走了6个来回.它一共走了多少米?