Question

小学分数计算题

看看怎么做？

Answer 1

这题对小孩确实难了

1/1*2*3+1/2*3*4+ +。。。。1/48*49*50
=1/2*(1/1*2-1/2*3)+1/2*(1/2*3-1/3*4)+....+1/2*(1/48*49-1/49*50)
=1/2*(1/1*2-1/49*50)
=0.49

Answer 2

(1×2×3)分之1+(2×3×4)分之1+...+(48×49×50)分之1
=(1×2)分之1-(2×3)分之1+(2×3)分之1-(3×4)分之1+...+(48×49)分之1-(49×50)分之1
=(1×2)分之1-(49×50)分之1
=2分之1-2450分之1
=2450分之1225-2450分之1
=2450分之1224
=1225分之612

Answer 3

=(1/2)(1/1x2-1/2x3)+(1/2)(1/2x3-1/3x4)+...+(1/2)(1/48x49-1/49x50)
=(1/2)(1/1x2-1/2x3+1/2x3-1/3x4+...+1/48x49-1/49x50)
=(1/2)(1/1x2-1/49x50)
=306/1225