+0.99-0.98-0.97+0.96+0.95-0.94-0.93+.+0.08+0.07-0.06-0.05+0.04+0.03-0.02-0.01

0
=(0.99-0.98)-(0.97-0.96)+(0.95-0.94)-(0.93-0.92)-.....- (0.03-0.02)-0.01
=0

（0.99-0.98-0.97+0.96）+（0.95-0.94-0.93+0.92）+.+(0.03-0.02-0.01)=0
0.01到0.99合计99个数,四个一循环到最后余0.03-0.02-0.01三项