2又1/2+5又1/4+8又1/8+11又1/16+14又1/32+17又1/64+20又1/128+23又1/256
=(2+5+8+11+14+17+20+23)+(1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256)
=(2+23)×8÷2+1/256×(128+64+32+16+8+4+2+1)
=200÷2+1/256×255
=100+255/256
=100又255/256
2又1/2+5又1/4+8又1/8+11又1/16+14又1/32+17又1/64+20又1/128+23又1/256
=(2+5+8+11+14+17+20+23)+(1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256)
=(2+23)×8÷2+1/256×(128+64+32+16+8+4+2+1)
=200÷2+1/256×255
=100+255/256
=100又255/256