(-1.25)+3.85+(+3.875)+(-3 1/4)+(-1/2)+1.15+(-3 7/8)
=(-1又1/4)+(3又17/20)+(3又7/8)+(-3又1/4)+(-1/2)+(1又3/20)+(-3又7/8)
=[(-1又1/4)+(-3又1/4)]+[(3又7/8)+(-3又7/8)]+[(3又17/20)+(1又3/20)]+(-1/2)
=[(-4又1/2)+(-1/2)]+4=(-5)+5
=0
(-1.25)+3.85+3.875+(-3 1/4)+(-1/2)+1.15+(-3 7/8)
=2.6+0.625+0.65+(-3 7/8)
=3.225+(-3.225)
=0