1-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-……-1/8-1/9+1/9+1/10
=1-1/2+1/10=3/5
1-1/2+1-1/4+1-1/8+……+1-1/256+1-1/512=9-(1/2+1/4+……+1/512)
=9-511/512=8又1/512
1/2-1/3+1/3-1/4+……+1/11-1/12
=1/2-1/12=5/12
更正：1-1/2+1-1/4+1-1/8+……+1-1/128+511/512=7-(1/2+1/4+……+1/128)+511/512
=7-127/128+511/512=7又3/512