0.5小时= 分钟,6分钟= 小时.
因为A×B=1,所以A=,B=.(A、B≠0) .
÷7=÷ =38.
× =× = ×= ×0.1=+ = ﹣.
× =× =+ =1.5× =× =1.
× =3600 × =3600 × =3600 × =3600 × =3600.