六年级奥数每日一题106:简便计算  1+1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90

六年级奥数每日一题106:简便计算 1+1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90

六年级奥数每日一题106:简便计算 1+1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
更新:2017-04-03 19:36:23    时长:05:57    播放量:1047