1,2,3,4,5,6,7,
1+2+3+4+5+6+7
1×2×3×4×5×6×7
1,2 ,3,4,5,6,7
:(1/2+2/3+3/4+4/5+5/6+6/7)+(1/2+2/3+3/4+4/5+5/6+6/7)*1/2—(1+
1/(2/3)/(3/4)/(4/5)/(5/6)/(6/7)/(7/8) 用简算
1/【2/3】/【3/4】/【4/5】/【5/6】/【6/7】/【7/8】
数字推理:1,4,3,5,2,6,4,7,
1\7;2\7;3\7;4\7;5\7;6\7以次类推找出规律
1 2 3 4 5 6 7 8=1
1+1+2+3+4+5+6+7+8+9.99?
1-1+2-3+4-5+6-7+.-2013+2014
1 2 3 4 5 6 7=1