(-2000+5/6)+(-1999+2/3)+4000+2/3+(-1+1/2) .急..

(-2000+5/6)+(-1999+2/3)+4000+2/3+(-1+1/2) .急..

原式=(-2000-1999+4000-1)+(5/6+2/3+2/3+1/2)=5/6+8/6+3/6=8/3