(8+0.8)*0.125=8*0.125+0.8*0.125=1+0.1=1.1
0.34*99+0.34=0.34*(99+1)=34
4*1.98*0.25=0.25*4*1.98=1*1.98=1.98
101*0.24=(100+1)*0.24=0.24*100+0.24=24.24
0.25应该为0.35要不然此题无简便运算.7.28×0.35－7.25×0.35 =0.35*（7.28-7.25）=0.03*0.35=0.0105
1.25*21.2*24=1.25*（20+4）*21.2=（25+5）*21.2=30*21.2=636