"Can we use old 1 sen coins in our daily transaction? I have many 1 sen coin at home and I don't know what to do with them. I tried bring it to bank before but they don't accept my 1 sen coin because they said it is not legal tender anymore. I try to find any information regarding 1 sen coin but most of the article is outdated. Can you give me advice about what can I do with my 1 sen coin?"