Question

一道数学题,请用简便方法计算:1又1/2-5/6+7/12-9/20+11/30-13/42+15/56

Answer 1

最简便的方法应该是：把1又1/2拆成1+1/2把5/6 1/2+1/3 7/12 1/3+1/4 9/20 1/4+1/5 11/30 1/5+1/6 13/42 1/6+1/7 15/56 1/7+1/8 这样一加一减的抵消 很方便就得出答案了

Answer 2

原式=1+1/2-(1/2+1/3)+(1/3+1/4)-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)+(1/7+1/8)
=1+1/2-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8
=1+1/8
=1又1/8