有理数加减法(要写过程)
-1/8+1/3-3/8+2/3
0-(1/2)-(-3.25)+2又3/4-(+7又1/2)
6又3/5+24-18+4又4/5-16+18-6.8-3.2
(-2/3)-(+3/4)-(-2/3)-(+3/4)
(-5又1/2)-(-7又1/3)-(+4又1/5)-6又2/3