Translation of centimeter in Spanish

I guess you know Spanish very well. I'm not on line most of the time. I think to get accommodation in the city is hard. I have many friends in Madrid, they all live outside the city. I think we can help each other to practice German or Spanish.
I understand that you use the article 'die' when talking about a feminine object, das when the subject is neutral, and der when talking about a masculine object. But how can you remember all these?
During my summer vacation I want to go to Italy for a month. I already look forward to it. I hope that our communication is helping you and I would be pleased about continuing writing mails.