214×27≈6000,积是四位数;214×27=5778586×38≈24000,积是五位数;586×38=22268416×62≈24000,积是五位数;416×62=25792702×94≈70000,积是五位数;702×94=65988520×83≈40000,积是五位数;520×83=431603600×50≈200000,积是六位数.3600×50=180000