解:原式=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)……(1-1/100)(1+1/100)=(1/2)(3/2)(2/3)(4/3)(3/4)(5/4)……(99/100)(101/100)=(1/2)(101/100) (中间约分而得)=101/200